The death toll from a brazen attack on Afghanistaninfo-icon's largest military hospital by terrorists disguised as medics has risen to 49 with dozens wounded, a senior healthinfo-icon official said on Thursday.

Salim Rassouli, director of Kabul hospitals, said 49 people had been killed in the attack on Sardar Daud Khan Hospital on Wednesday and at least 63 were injured.

Some uncertainty remained over the exact figures and one security official said more than 90 people had been wounded. Earlier estimates had put the number of dead at 38, with 70 injured.

The Islamic Stateinfo-icon claimed the attack through its Amaq news agency. The group also posted photos that it said were taken by its fighters within the hospital and an image of the five fighters who were purportedly involved in the attack.

The terrorists rampaged through the 400-bed hospital, shooting doctors, patients and visitors and battling security forces for almost six hours in a sophisticated operation.Survivors spoke of barricading themselves in hospital rooms to escape the terrorists who were armed with automatic weaponsinfo-icon and grenades and who began their attack after a suicide bomber blew himself

up at a backdoor entrance.

Mohammad Nabi, a doctor at the hospital who escaped with a broken leg, said it had been difficult to comprehend what was going on initially as the terrorists in doctors' white coats took out concealed weapons and began shooting.

"We were shocked when we saw AK-47s in their hands firing," he said. "They killed our patients in their beds and they killed our doctors."The attack on the military hospital, located close to the heavily fortified USinfo-icon embassy, underlined warnings from security officials of an increase in high profile attacks in Kabul this year.

The UN Security Council issued a statement condemning the attack and urging all states to cooperate with the Afghan government to bring those responsible to justice and to prevent and suppress the financing of terrorism.

Afghans mourned as funerals were underway following the deadly attack.Defence ministry spokesman Mohammed Rodmanesh said experts were scouring every inch of the hospital, badly damaged during the attack, for evidence of the IS claim.

Rodmanesh said despite the IS claim, Afghan authorities "must do our own investigations to know who is responsible".Afghan forces have been under increasing pressure by the Taliban and also from IS militants, mostly in country's east.

IS fighters, most believed to be former members of the Pakistaninfo-icon-based Tehrik-e-Taliban Pakistan (TTP), have established a stronghold in the eastern Afghan province of Nangarhar on the border with Pakistan. The IS fighters are battling both Afghan security forces and the Taliban.

Despite repeated strikes by US and Afghan forces which American commanders believe have killed a third of their fighters, they have also claimed several high profile attacks in Kabul that killed scores of people.