SINGAPORE/JAKARTA/KUALA LUMPUR -- On the 23rd consecutive day of "unhealthy" air readings in Singapore, a new record, anti-pollution campaigner Low Ying Hui stood up at a town hall and blamed Indonesians for the haze shrouding the city-state.

"This is not a natural disaster," Low Ying Hui, president of the People's Movement to Stop Haze, a Singapore-based nongovernmental organization, told a town hall meeting on the crisis attended by 80 people.

Earlier in the month, the Pollutant Standards Index (PSI) levels had reached "very unhealthy" levels, and Singapore was ranked the world's most polluted city by air-quality monitoring company IQAir.

Low accused plantation companies in Indonesia of draining peatlands, arguing the haze affecting Singapore originates from fires linked to plantation companies in Indonesia. He said those companies drain peatlands to grow crops such as oil palm and acacia, which is used to make paper. Draining the land dries the peat and makes it more likely to catch fire.

"Children's asthma gets worse," one attendee said during what became a heated debate on the pollution's effects "I don't want to see this happen again. I've become so frustrated after all these years." Economic losses from the 2026 haze could reach between 3.2 billion Singapore dollars ($2.5 billion) and SG$3.9 billion, potentially more than double the SG$1.83 billion lost during the last significant haze crisis, in 2015, according to a preliminary assessment by Euston Quah, an economics professor at Nanyang Technological University.

Showers this week, in both Singapore and Indonesia, have pushed PSI readings down to "moderate" levels. But facing such public anger, potential economic losses and reputational damage -- the nation hosted its annual Formula One motor race when the pollution was close to its worst -- it is not surprising the government decided to act.

However, academics and activists say events of the past 10 days have shown how hard it will be for Singapore to prevent future haze crises when events occur beyond its jurisdiction and it must rely on decisive action by the Indonesian government, something many critics argue has been lacking for the past 20-plus years.

"The root problem is forest and land fires. As long as that remains unresolved, the problem will continue," Shofwan Al Banna Choiruzzad, associate professor in the Department of International Relations at the University of Indonesia, told Nikkei Asia.

Indeed, when asked about the haze earlier this month, Syahganda Nainggolan, head of the Indonesian Government Communications Agency, was quoted by local media as replying, "We're not just sending over the haze. When there's no haze, we send oxygen.

The oxygen in Singapore and Malaysia comes from our forests, right? We hope our neighbors understand that this is beyond human error; this is truly nature." Many Indonesian officials have cited this year's severe El Nino weather phenomenon for exacerbating the scale of the crisis The Singaporean government's approach was initially to play hardball. Singapore's National Environment Agency (NEA) issued preventive measure notices to 10 companies in Indonesia over the fires.

The companies include Bumi Andalas Permai, Bumi Mekar Hijau, SBA Wood Industries and seven others. Some of them supply Asia Pulp & Paper, an Indonesian pulp and paper giant that also has operations in Singapore.

According to the NEA, the 10 companies operate in the palm oil or forestry sectors, and either hold land concessions in Indonesia where fires have been recorded or are linked to companies that do. Then, on Oct. 23, the NEA asked 10 Singapore-based companies, including Singapore-listed agribusiness group Wilmar International, to provide documents and information as authorities stepped up their scrutiny. Minister for Sustainability and the Environment Grace Fu said on Facebook on Oct. 23, "This is an important next step in establishing the facts and gathering the evidence needed to determine whether companies have contributed to the haze."

Under the notices, the companies must halt any burning in progress and submit plans to NEA detailing how they will extinguish the fires and prevent them from recurring. The action was taken under the Transboundary Haze Pollution Act (THPA) enacted in 2014 following earlier episodes of severe haze.

Companies found guilty under the law face fines of up to SG$100,000 per day, up to a maximum of SG$2 million. However, the legislation has hitherto proved largely ineffective; some cases opened during the 2015 haze crisis remain unresolved.

Smoke rises from peatland in the Indonesian province of West Kalimantan on the island of Borneo, which was severely damaged by a fire last month.

Indonesia did not respond positively. Ministers and other officials took umbrage at what they saw as meddling in the country's internal affairs: the antithesis of the nonconfrontational "ASEAN way." Last Saturday, Jakarta reduced gas supplies to Singapore by about 8%, and ministers -- without naming names -- accused certain countries of not being good neighbors. Indonesian Energy Minister Bahlil Lahadalia said his country was reconsidering a plan to sell electricity to Singapore.

Meanwhile, myriad commentators accused Singapore of hypocrisy. These included former Indonesian Trade Minister Muhammad Lutfi, who questioned why Singapore was targeting plantation operators in Indonesia rather than examining parent companies and shareholders based in Singapore and Malaysia.

Indonesian officials insisted the government had taken steps to address the haze problem. President Prabowo Subianto described the forest and peatland fires as a "crime against humanity," during a cabinet meeting on Oct. 21 marking his administration's second anniversary.

"We must not take this lightly. We will respond on a massive scale and investigate it thoroughly. This time, we can no longer act as usual," he said. "If the evidence is clear, we will take action. We will revoke the permits of all companies found to have violated the law." Indonesian National Police Chief Suyudi Ario Seto said investigators were handling 98 corporate-related fire cases and gathering evidence that could support charges against company owners and shareholders. He also alleged that foreign parties from an unnamed neighboring country may have been involved.

The Indonesia Stock Exchange on Oct. 15 sought clarification from several listed plantation companies, including oil palm producer Bakrie Sumatera Plantations, palm oil company Sinar Mas Agro Resources and Technology, and plantation group Astra Agro Lestari about the potential effects of the fires on their operations and earnings.

Bakrie Sumatera Plantations acknowledged the company or its subsidiaries could face legal proceedings but said it did not expect a material impact on its business. Astra Agro Lestari said employees of its subsidiary, Subur Agro Makmur, had been questioned over fires at one of its sites, although no administrative sanctions had been imposed.

An APP spokesperson told Nikkei Asia that Bumi Andalas Permai, Bumi Mekar Hijau and SBA Wood Industries were independent suppliers rather than subsidiaries, and that concession operators were best placed to comment on fires within their areas. APP said its firefighting system included more than 6,000 people as well as helicopters, drones and monitoring equipment.

Low Ying Hui, president of the People’s Movement to Stop Haze, a nongovernmental organization in Singapore, discusses with local residents the effects of haze on their daily lives on Oct 25.

Observers say Indonesian ministers were also playing to the domestic audience, stoking nationalist sentiment to divert attention from their failure to tackle the haze.

"Singapore may not be entirely right, but this remains the Indonesian government's responsibility to improve forest governance," said Suraya Afiff, an environmental anthropologist at the University of Indonesia and longtime forest activist.

But with bilateral tensions escalating rapidly, Singapore -- which depends heavily on its neighbors for resources, including energy and water -- changed tack. Foreign Minister Vivian Balakrishnan went to Jakarta on Tuesday, where, after meeting his counterpart, Arrmanatha Nasir, the two governments agreed to set up a joint task force to seek corporate accountability for forest fires.

The following day, he met Prabowo and acknowledged to the media afterwards that "when transboundary events occur, there's a need for high-level direct communication between governments ... looking for solutions. It's essential in times like this to keep looking out for cooperative, collaborative, constructive solutions." Vehicles can barely be seen as they drive through the thick haze from forest fires on the outskirts of the city of Pontianak, in West Kalimantan, Indonesia.

On Wednesday Singapore also summoned executives from some of the companies it had served notices on to warn them -- and parade them before the cameras. Minister Fu said the THPA would be amended to make it easier to prosecute companies that had allegedly started fires.

Michelle Lim, an associate professor of law at Singapore Management University, said the country's two-pronged approach was more appropriate than simply using domestic legislation. "The reason why there have yet to be any successful prosecutions is the difficulty in obtaining evidence in a foreign country," she told Nikkei Asia. "So cooperation by the foreign country (Indonesia) would go a long way to facilitate obtaining the evidence needed."

Lim described the joint committee as a "good thing" because the current ASEAN Agreement on Transboundary Haze Pollution "is not efficient or effective enough."

Choiruzzad said the initiative could become a starting point for stronger regional cooperation, including with Malaysia and other ASEAN countries. But he added, "I'm skeptical it will be followed through. The government hasn't even agreed to declare a national disaster, let alone work with another country to identify those responsible. We need to see the evidence." Singapore Foreign Minister Vivian Balakrishnan, left, greets his Indonesian counterpart, Arrmanatha Nasir, during their meeting in Jakarta on Oct. 27.

Lim said Singapore could technically seek redress under international law. However, taking Indonesia to an international court or arbitration would have serious diplomatic implications.

For companies not registered in Singapore, establishing the offence would be more difficult. Lim said the THPA has extraterritorial reach, as it covers haze in Singapore caused by fires outside the country. But obtaining evidence would be difficult without cooperation from the Indonesian authorities.

Even without a conviction, the investigation could influence corporate behavior by exposing companies to reputational pressure. Six of the 10 Singapore-based companies issued with legal notices said they would cooperate with requests from the National Environment Agency, local media reported.

The response from Malaysia, which shares the island of Borneo with Indonesia, has been less forceful, even though several states and federal territories ordered schools to close or switch to remote learning because of the deteriorating air quality.

The Malaysian government has declined to pursue legal action, citing insufficient evidence. Government spokesman Fahmi Fadzil said, "Plantation and Commodities Minister Datuk Seri Noraini Ahmad informed the cabinet that cross-checks with Malaysian companies holding oil palm concessions showed that most burning activities did not occur within [their concession areas]." Singapore's Marina Bay Sands resort stands out against the haze on Oct. 23. Economists warn the weeks of pollution could significantly affect the economy.

The Malaysian Palm Oil Board will continue to engage with Malaysian plantation companies operating in Indonesia," Fahmi said.

Critics argue that numerous independent sources of data already exist, and that Singapore is using this information as a basis for its crackdown. Former Malaysian lawmaker Lee Chean Chung, a leader of the Bersama party, criticized the government for failing to adopt stronger measures. Quoting comments by Prime Minister Anwar Ibrahim, Lee Chean Chung said, "The prime minister says we've done everything we can, but we haven't legislated, named companies or used our financial regulators." Referring to Singapore's response, he said, "Singapore has done all three. The intent is right, but the tools are too weak."

Meenakshi Raman, president of the environmental nonprofit Friends of the Earth Malaysia, called for closer coordination among the three countries affected. "We urge the heads of the governments of Malaysia, Singapore and Indonesia to jointly address the public in these three countries to explain to us their long-term joint plans and coordination to end the transboundary haze crisis once and for all," she said. Fathiya Dahrul and Amy Chew are contributing writers.