Gunmen stormed a military hospital in Afghanistan's capital on Wednesday, killing at least four people and wounding more than 60, setting off clashes with security forces that were still underway hours later.

Gen. Dawlat Waziri, a Defense Ministry spokesman, said an unknown number of gunmen entered the Sardar Mohammad Daud Khan Hospital after an explosion and gunfire. The 400-bed military hospital is located near two civilian hospitals in the Wazir Akbar Khan area of Kabul, which is also home to several embassies.

Health Ministry spokesman Ismail Kawasi said at least three bodies of civilians and more than 60 wounded people had been brought to nearby hospitals, adding that the toll was likely to rise as ambulances were still at the scene.

Waziri said Afghan forces had battled the attackers floor by floor, and were carrying out a clearing operation on the 6th and 8th floors of the complex. He said a suicide bomber had detonated his payload and another attacker was shot dead, and that one member of the security forces was killed and three others wounded.

Afghan helicopters circled over the area, which was surrounded by security forces.

Abdul Qadir, a hospital worker who witnessed the attack, said an attacker in a white coat shot at him and his colleagues. He added that there were seven patients prepared for surgery at the operation theater where he works at the time of the attack.

President Ashraf Ghani condemned the attack during an address in honor of International Women's Day, calling it "an attack on all Afghan people and all Afghan women."

No one immediately claimed the attack, and the Taliban denied responsibility.

The assault on the hospital came exactly a week after the Taliban launched a complex attack in Kabul targeting security forces that killed at least 22 people and set off clashes that lasted several hours.