A wing of a four-story hospital being rebuilt in the Afghan capital collapsed Monday, injuring at least 14 people, and rescue workers hurried to reach others feared trapped in the rubble.

Witnesses and police said a 120-foot section of the concrete structure, which had been stripped bare and enclosed with scaffolding, crumbled without warning. There was no sign of any explosion.

At the back of the building, rescuers dug with their hands to try to free a man buried to his waist in rubble and screaming in pain. Earth-movers and cranes also were being used in the rescue effort.

By early evening, 14 injured Afghans had been pulled from between slabs of shattered concrete, said Hakim Aziz, a senior health ministry official.

"The rescue teams are working as fast as they possibly can," to find any others who might still be trapped, he said.

Three people were seriously hurt, and two of them were taken to a field hospital operated by NATO's (search) security force in the capital. No bodies were immediately found, although hospital workers said they feared some of their colleagues had been killed.

The Jamhuriat Hospital (search), located in the center of Kabul (search), was being refurbished by a Chinese-Afghan construction consortium.