Sohrab Faqiri spent Eid, the Muslim festival to mark the end of the fasting month of Ramadan, looking for the grave of his brother, killed in a massive Pakistan airstrike on Kabul this week.

Pakistan’s bombardment campaign, on what it says is terrorist and military infrastructure in neighbouring Afghanistan, appeared to have gone catastrophically wrong. A rehabilitation centre for drug addicts was hit on Monday night, according to the United Nations and the Afghan authorities. The UN’s preliminary death toll is 143 people, while the Taliban administration puts the figure at more than 400 dead.

Faqiri’s brother, Qais, a tailor and father of a 10-year-old boy, was being treated for the last three months at the facility, called Omid or “Hope”. Faqiri rushed there after the airstrike, but could not find him among the survivors. He spent the next two days visiting hospitals in Kabul, but there was no sign of Qais. Then, by chance, he saw a video of a mass burial by the authorities of the airstrike victims and spotted his brother.

On Thursday – marked as Eid in Afghanistan – he went to the hillside graveyard on the edge of Kabul, where the burial took place. There, he found rows of stones planted along lines of upturned earth. But there were no names to identify any of the bodies.

“Worst of all is that his grave is not known to us,” Faqiri said, speaking at the cemetery, bursting into tears. “This is the saddest moment, for a person on Eid day to search for the body of his brother.” He has not had the heart yet to tell their mother.

The attack took place just as patients returned to their dormitories after gathering for Tarawih, the special prayers said at night during Ramadan, when worshippers ask for forgiveness of their sins.

Wali Nazir Mohammad, 23, was tired after the prayers and went to his bed, in one of the smaller buildings which accommodated about 20 patients in a single room. When the explosion woke him, the room and some of his fellow patients were on fire. Many in the room were dead and others were screaming for help.

His waist and leg were in severe pain. He said that the room had not been hit directly, but shrapnel came through the walls, slicing into him. Around half an hour later, an ambulance took him to Wazir Akbar Khan hospital, one of Kabul’s main medical facilities. He said one of the big buildings had taken a direct hit.

“I have a message for our government: please take our revenge,” Mohammad said, speaking from his hospital bed. “If the government cannot take our revenge, I ask them to give us weapons.”

Juma Khan Nael, from the Afghan Red Crescent Society, part of the International Federation of Red Cross and Red Crescent Societies, said many of the patients had finished their treatment and were due to be discharged the following day. He said the fire ignited by the bombing could be seen for miles.

“That fire was unthinkable, it could not be controlled, no one could help those trapped by it,” he said.

When Nael arrived at the site on the morning after the bombing, rescue workers were still digging through the debris. They were finding hands, feet and pieces of flesh, not whole bodies. The smell of burnt meat hung in the air.

Maisam Shafiey, from the Norwegian Refugee Council aid group, said when he got to the scene the next morning, smoke was still rising, while in another part of the site, some patients remained.

Shafiey believed many of the victims had been together in one large structure. “A big building was hit. There’s nothing there now. The roof had collapsed. Everything was rubble,” he said.

Afghan authorities say 408 were killed and 265 injured. Islamabad, which maintains that it struck a military target, says that terrorists attacking Pakistan are being harboured by the Taliban.

Georgette Gagnon, the deputy head of the UN mission in Afghanistan, expected her organisation’s death toll to rise. She said “several hundred” appeared to have been killed and injured.

She said the drug treatment centre was within a facility run by the Afghan de facto administration. Before 2015, the location was a US military base. “We call on the parties to de-escalate and re-commit to a ceasefire,” she said.

Dejan Panic, the country director of Emergency, an Italian NGO which runs a major hospital in Kabul, said he had heard two loud detonations; the airstrike took place about six miles away across the city.

The hospital received 24 wounded and three dead bodies that night, with many having shell injuries – metal shrapnel entering their bodies. These days, such injuries were rare in Afghanistan, Panic said, compared with the war years before the 2021 Taliban takeover.

One man had broken his thigh bone jumping out of a second-floor window to escape the fire. Another was in danger of bleeding to death with a severed femoral artery, which carries blood to the legs, but was brought to the hospital in time to be operated on.

The less-injured patients told Panic they were happy about their treatment at the rehab facility. Drug addicts were a common sight in Kabul before the Taliban seized power, but have been taken off the streets. At the Omid centre, patients were being taught skills such as carpentry, tailoring and electrical work.

“The patients said that they were getting good food, clothes, and a second chance in life,” said Panic.