A Pilgrim and a Retiree: Victims of the Houthi Airport Attack in Saudi Arabia The strike was the Iran-backed militia’s most lethal against the kingdom, by far, during their long conflict.

Mohammad Nasrullah was boarding a flight to Mecca, Islam’s holiest city, leading a group of pilgrims from Bangladesh. Buthaina Owaida, a Syrian woman who had moved to Saudi Arabia, was on the phone with her grandson.

Mahmoud Barqawi was working in a restaurant at the airport, hoping to save enough money to build a home back in Jordan.

All three were among the people killed on Saturday afternoon when a cruise missile launched by Yemen’s Houthi militia smashed into Terminal 3 of the international airport in Riyadh, Saudi Arabia’s capital.

The attack by the Houthis — an Iranian-backed militia that has been battling Saudi Arabia on and off for more than a decade — set the terminal ablaze and brought chunks of the roof crashing down on travelers, killing at least 13 people and wounding more than 300, the Saudi authorities said. Saturday’s assault was the deadliest in a Gulf Arab country since the U.S.-Israeli war with Iran began in February.

It was also the Houthis’ most lethal attack, by far, during their long conflict with Saudi Arabia, which continues to escalate. On Tuesday night, explosions rocked the Saudi and Yemeni capitals as the two sides exchanged intense strikes. Days after the calamity at the airport, Saudis and foreign residents of the kingdom are still in shock, struggling to make sense of what happened.

“There is no justification for targeting civilians,” said Majed Alessa, a 25-year-old engineer said he had been eating lunch in an adjacent terminal and had just opened a book when he saw the blast through the panoramic windows.

He was shaken but unscathed. “What happened to these innocent people — they have nothing to do with anything,” he said. Mr. Nasrullah, 37, was an Islamic studies teacher in Bangladesh and father of three, according to his brother, Mohammad Ahsanullah. Ms. Owaida, a 56-year-old mother of four, was described by her sister, Hayat Owaida, as a “very compassionate” woman who would sometimes “laugh so much until she cried.”

And Mr. Barqawi, 33, left behind two sons, aged 4 and 1, his mother said.

Like many of the kingdom’s foreign residents — they make up around a third of the population — he had come in search of work. “He was an innocent man,” said Lina Barqawi, his mother. “He did no harm, he was always kind to everyone, and went out of his way to help people. Why did they kill him?”Smoke and Blood Surveillance videos released by the Saudi government showed passengers lining up to board an airplane, clad in the simple white that pilgrims wear to Mecca, when the missile struck with a blinding flash.

From Terminal 4, Mr. Alessa saw a black plume of smoke as the travelers around him sprang into action, trying to help one another as they evacuated, he said. Outside, he encountered someone dazed and covered in blood.

That person described how he had tried to perform first aid on a young man next to him, only to realize that the man’s skull had been shattered, Mr. Alessa recounted. In an interview with Al Arabiya, a Saudi news network, a doctor at one of the largest hospitals in the city described how the staff mobilized to treat a flood of trauma patients from the attack, setting aside 100 beds in their emergency department. The hospital’s staff performed 22 surgeries in less than 24 hours, the doctor, Omar al-Obaid, said.

Those seriously wounded included Muhammad Rabbani, a 30-year-old Indian who worked in the airport as a vending machine technician, according to his cousin, Muhammad Ummer.

He remains in intensive care.

“The entire family, especially his parents, are extremely worried,” Mr. Ummer said. “We are desperately waiting for some good news about his recovery.”

Among those whom doctors could not save were Azza Ramzi, a 28-year-old Egyptian flight attendant, and Talal Dani, a 60-year-old Palestinian retiree. Mr. Dani — survived by his wife, four sons and two daughters — had lived in Saudi Arabia his whole life, according to his brother, Ahmed Dani. Targeting Airports Soon after Saturday’s attack, a Saudi military spokesman, Turki al-Maliki, decried the strike as terrorist act and “full-fledged war crime.”The Houthis, in turn, said that their attack was in retaliation for deadly Saudi airstrikes in Yemen, including many that have killed and injured civilians, and strikes against civilian airports there.

Asked why the Houthis would target an airport full of civilians, Mohammed al-Bukhaiti, a Houthi political official, said that Saudi Arabia bore responsibility for the civilian casualties “because it failed to evacuate its airports” after the militia had warned of its plans to attack them. Tensions began to escalate in July after Yemen’s Saudi-backed government said it had struck the airport in Yemen’s capital, Sanaa, to prevent the landing of an unauthorized Iranian plane.

The Houthis blamed Saudi Arabia.

Last week, after a full-blown war reignited between Saudi Arabia and the Houthis, the militia turned its focus squarely on Saudi airports, threatening to turn them into a “theater of military operations.”Since then, at least 18 people were killed across five aerial assaults on Riyadh’s airport.

A Close Call In one of those attacks, two days before the catastrophic strike on the airport, an unidentified projectile hit a Saudi Airlines plane on the tarmac. Noora al-Otaibi, a 35-year-old Saudi doctor who was traveling to see her family in the coastal city of Jeddah, said she had just boarded an adjacent plane when there was an enormous blast.

She realized that the neighboring plane was on fire and felt like she had been plunged into a horror movie, she said.

After she left the plane, Dr. al-Otaibi — an intensive care physician — rushed to help others, including a woman who had fainted as ambulances raced to the scene. Three people were killed in that attack.

Dr. al-Otaibi had known that the Houthis posed a threat, but she had never imagined that they would target an airport, she said. “What I’ve been through, and the terror I still feel inside — I would never wish it upon anyone, even an enemy,” she said.

After months away from her family, Dr. al-Otaibi was determined to see them and returned to Riyadh’s airport the next day for a new flight. Periodic announcements warned people to keep away from windows, she recalled.

She remained on high alert, she said, amazed that her fellow travelers did not seem more bothered. Dr. al-Otaibi arrived in Jeddah safely.

“I am with my family and in my home,” she said, “but I feel numb.”The following day came the deadliest attack of all. Ismaeel Naar, Rania Khaled, Shuaib Almosawa, Saif Hasnat, Abu Bakr Bashir, Anjana Sankar, Rana F. Sweis, Muhammad Haj Kadour, Sarah Chaayto, Raja Abdulrahim contributed reporting.

Vivian Nereim is the lead reporter for The Times covering the countries of the Arabian Peninsula.

She is based in Riyadh, Saudi Arabia.