Heavy casualties were feared in Kabul after a hospital that treats drug users was hit by airstrikes, which Afghanistan blamed on Pakistan’s military.

Pakistan dismissed the accusation, saying the strikes on Monday – which were also launched against eastern Afghanistan – did not hit any civilian sites.

Sharafat Zaman, the health ministry spokesperson, gave a preliminary death toll of 200 during a television interview with local media that was posted on X. He said all parts of the drug treatment hospital had been destroyed.

Afghanistan’s deputy government spokesman Hamdullah Fitrat later said the death toll had “so far” reached 400 people, while about 250 people had been reported injured.

Local television stations posted footage of firefighters struggling to extinguish flames among the ruins of a building.

AFP reporters at the site counted at least 30 bodies as medical teams worked to help the wounded, who were taken to several hospitals for treatment, according to a source working with the rescue operation.

The alleged attack came hours after Afghan officials said the two sides had exchanged fire along their common border, killing four people in Afghanistan, as the deadliest fighting between the neighbours in years entered a third week.

Afghanistan’s government spokesperson Zabihullah Mujahid had earlier condemned the strike on X, before the death toll had become apparent, saying it violated Afghanistan’s territory. He said most of those killed and wounded were patients undergoing treatment at the facility.

A spokesperson for Pakistan’s prime minister, Shehbaz Sharif, dismissed the allegations as baseless, saying no hospital was targeted in Kabul.

In a post on X, Pakistan’s ministry of information said the strikes “precisely targeted military installations and terrorist support infrastructure including technical equipment storage and ammunition storage of Afghan Taliban” as well as Afghanistan-based Pakistani militants in Kabul and Nangarhar, saying the facilities were being used against innocent Pakistani civilians.

It said Pakistan’s targeting was “precise and carefully undertaken to ensure no collateral damage is inflicted”. The ministry said Mujahid’s claim was “false and misleading” and aimed at stirring sentiment and to cover what it described as “illegitimate support for cross-border terrorism”.

Dejan Panic, Afghan director of the Italian NGO Emergency, said it had received three bodies after the strike on Monday night and was treating 27 wounded.

Witnesses reported severe damage to the hospital building, with sections collapsing after the strike. Firefighters struggled to control the flames while rescue teams searched through the rubble for survivors. Rescue efforts were complicated overnight by limited visibility.

“We were inside the wards when the explosion happened,” said Yousaf Rahim. “My bed was in the corner, and I suffered injuries to my leg and thigh. It was a horrific scene. Patients fell from their beds, screaming and running as fire and smoke filled the wards and rooms.”

“Thick smoke and dust spread throughout the hospital,” he added. “Many people lay on the ground. Dozens died instantly, and the critically injured were pleading for help. I didn’t know what to do. I stepped over bodies and managed to escape outside.”

Fereshta Abbasi, a researcher for Human Rights Watch, said the organisation was very concerned about reports of mass casualties, and called on authorities to promptly investigate the incident. “Civilian facilities must never be targeted or put at risk of disproportionate attack,” she said.

It came hours after the UN security council called on Afghanistan’s Taliban rulers to immediately step up efforts to combat terrorism. Pakistan accuses Kabul of harbouring militant groups, particularly the Pakistani Taliban, which it says carry out attacks inside Pakistan.

The security council resolution, adopted unanimously, did not name Pakistan but condemns “in the strongest terms all terrorist activity including terrorist attacks”. The resolution also extends the UN political mission in Afghanistan, Unama, for three months.

Pakistan’s government often accuses Afghanistan’s Taliban government of providing safe haven to the Pakistani Taliban, which is designated as a terrorist organisation by the US, as well as to outlawed Baloch separatist groups and other militants who frequently target Pakistani security forces and civilians across the country. Kabul denies the charge.

Earlier, Afghan officials said four people, including two children, were killed and 10 other people were wounded in south-eastern Afghanistan in Monday’s exchange of fire. Mortar shells fired from Pakistan overnight struck villages in Khost province and destroyed several homes, said Mustaghfar Gurbaz, a spokesperson for the provincial governor.

On Sunday, Pakistan said a mortar fired from Afghanistan hit a house in north-western Bajaur district, killing four members of a family and wounding two others, including a five-year-old. Residents and officials said the military on Monday targeted Afghan positions along the border, where Sunday’s attack originated.

There was no immediate comment from Pakistan, which repeatedly has said its military only targets Afghan posts and militant hideouts.

Islamabad has described the situation as an “open war”. The cross-border clashes have included multiple Pakistani airstrikes on Afghanistan’s capital, Kabul.

The fighting began in late February after Afghanistan launched cross-border attacks in response to Pakistani airstrikes inside Afghanistan that Kabul said killed civilians. The clashes disrupted a ceasefire brokered by Qatar in October after earlier fighting killed dozens of soldiers, civilians and suspected militants.

Haroon Janjua contributed additional reporting