Attack risks rise for tankers as Iran vows to block more Hormuz routes By Jonathan Saul and Parisa Hafezi LONDON, Oct 8 - Tankers are facing a higher risk of attacks and intimidation as they try to get critical shipments through the Strait of Hormuz after Iran issued new warnings it would block routes that it has not authorized, sources said.

Last week already saw the biggest number of attacks on tankers in the key waterway since the Iran war began - cutting the number of vessels trying to get through to the lowest in more than two months.

Iran has now warned regional countries that any attempt to open new routes for oil exports would be considered hostile, a senior regional official close to Tehran told Reuters. It was part of a plan agreed by both Iran's political leaders and its Revolutionary Guards, the official added. 'POLICY OF FEAR AND THREATS' "Iran has absolutely no intention of allowing control of the Strait of Hormuz to slip from its hands, and has plans ready to block routes that some regional countries have for exporting oil," a senior diplomat in the region briefed by Tehran told Reuters separately.

"This could involve missile and drone attacks on ships, or sending boats to scare ships away," the diplomat added. "It plans to continue this policy of fear and threats," he said.

In recent months, Gulf oil producers have rushed shipments of oil through channels that hug the Omani side of the strait before transferring the oil in open waters in the Gulf of Oman with aerial support from the US, sources have told Reuters.

In the latest incident in the past 24 hours, projectiles struck a tanker some 51 nautical miles off the coast of Qatar inside the Gulf, British navy agency UKMTO reported. Maritime security sources said the Antigua and Barbuda-flagged chemical tanker Acers had been hit by multiple projectiles north of Qatar's Madinat ash Shamal with minor injuries sustained by its crew.

“The Acers strike raises the prospect of a wider combat area affecting approaches to Qatar, Bahrain, Saudi Arabia, Kuwait and Iraq,” maritime risk intelligence group Pole Star Global’s subsidiary Clearwater Dynamics said in a report on Thursday.

The vessel's operator, listed in shipping databases as Antigua and Barbuda-based Valvoria Shipping, could not be reached for comment.

"The recent spate of Iranian attacks seems to have dampened the appetite of shipowners to sail through the Strait," said Jakob Larsen, chief safety & security officer at shipping association BIMCO. "The Iranian threat appears to have increased." 'WAR AT SEA DOES NOT REMAIN AT SEA' US President Donald Trump is weighing next steps against Iran, including whether to escalate strikes before or after the November midterm elections, which will decide control of Congress, as he presses a naval blockade meant to pile economic pressure on Tehran to reach a deal to end the conflict.

The war — and its $3 billion monthly price tag — has become a key issue on the campaign trail.

Governments and energy companies have drawn oil from stockpiles to alleviate pressure in a global oil market facing unprecedented supply disruptions this year, also caused by the war in Ukraine.

The amount of oil in storage that is accessible to the global market is running low, industry executives said at a forum in London this week, making the market more fragile and putting upward pressure on prices.

The impact of the crisis was increasingly rippling across the global economy. Danish shipping group Maersk said on Thursday it was increasing its emergency fuel surcharge on inland transportation in the UK and Ireland due to the ongoing conflict in the Middle East.

"There is no going back to the old world, no harboring back to the stability and the prosperity of the last several decades," Major General Paul Maynard, Assistant Chief of the Naval Staff with Britain's Royal Navy, told a UK Chamber of Shipping Riviera conference in London this week. "A war at sea does not remain at sea."