Attackers have stormed the largest military hospital in Kabul and a gun battle is under way, the Afghan defence ministry says. One doctor said he saw a gunman wearing a medic’s coat pull out a concealed assault rifle and open fire. One person has been killed along with one of the attackers and all patients have been evacuated, officials say. The so-called Islamic State (IS) group has claimed the attack via its Amaq news agency. President Ashraf Ghani said the attack at the 400-bed Sardar Daud hospital “trampled all human values”. “In all religions, a hospital is regarded as an immune site and attacking it is attacking the whole of Afghanistan,” he said. The attack began at 09:00 local time (04:30 GMT) when one militant detonated his explosives at the southern gate of the hospital – which is near the US embassy – and three other attackers entered the compound. They entered the second and third floors of the hospital carrying small arms and hand grenades and began shooting. “I saw a suicide attacker wearing a white coat open fire on me, I jumped from the stairs, then he opened fire on one of my colleagues,” said Abdul Qadir, a doctor who managed to escape. Another hospital staff member wrote on Facebook: “Attackers are inside the hospital. Pray for us.” Afghan commandos descended into the hospital compound from helicopters while security forces sealed off the streets outside. One of the attackers has been killed and the others were hiding under stairs and in bathrooms, a defence spokesman said. At least 29 people have been injured; Tolo TV quoted the health ministry as saying.