Security forces in Afghanistan on Wednesday killed a number of armed men who attacked the Sardar Daud Khan military hospital in the capital, Kabul, ending an assault that had lasted several hours.

"The operation has ended. All the attackers have been killed. We are still assessing the damage," Interior Ministry spokesman Sediq Sediqqi tweeted.

More than 30 people were killed in the attack, and over 50 wounded, the Defense Ministry said.

Ministry spokesman Dawlat Waziri said that four attackers had been involved and that all had been killed. Two suicide bombers detonated explosive vests inside the hospital. Two gunmen were were shot dead by security forces. Witnesses said at least some of the attackers, who entered the building and opened fire on staff and patients, were wearing white laboratory coats. The attack began after one of the suicide bombers blew himself up at the back entrance to the facility, which has some 400 beds and looks after wounded from all over the country.

Afghan special forces launched an hours-long clearance operation to remove the attackers from the building, evacuating all surviving patients and staff in the process.

Claim by 'Islamic State'

Medical facilities have frequently formed the target of militant attacks in Afghanistan.

The country's main rebel group, the Taliban, has denied responsibility for this one, as it mostly does in the case of attacks on hospitals or when a high number of  civilian casualties are involved.

Instead, the assault was claimed by "Islamic State" (IS) jihadists via a verified Telegram account.

IS put casualty numbers much higher than Afghan authorities, saying its fighters had killed at least 100 people.

The U.N. Security Council strongly condemned the "heinous and cowardly terrorist attack", saying that the perpetrators, organizers and financiers needed to be held responsible. 

Troubled security

Wednesday's attack comes just a week after simultaneous Taliban suicide assaults hit two security compounds in Kabul, killing 16 people.

The security situation in the country continues to be unstable, with security forces bracing for the start of the Taliban's fighting season in the spring after repeated bids to launch peace negotiations with the group have failed.

Afghan forces have been struggling to put down the Taliban insurgency on their own since US-led NATO troops ended their combat mission in December 2014.

tj/mb/jm (AFP, dpa, Reuters)