About 40 prisoners including fighters of the former ruling Taleban are being hunted after escaping from jail, say officials in southern Afghanistan.
The inmates are thought have escaped through a tunnel at the jail in Kandahar on Friday night, the BBC has been told.
Kandahar was a traditional stronghold for the Taleban and it is thought the escapees could easily blend in there.
The breakout was discovered on Saturday
when guards went to check on inmates.
A senior security official in Kandahar has refused to confirm exactly how many inmates escaped - or how they did it.
"Last night, a group of Taleban and political prisoners did
escape but we don't know how many," the official, named as General Salem, told Reuters news agency.
The BBC's correspondent in Afghanistan Crispin Thorold said it is thought all the men were being held in the same room.
Military spokesman General Abdul Wase told
AFP news agency that most of those held in the jail were "criminals" arrested during military
operations or on the basis of security intelligence.
Police and the army would hold separate inquiries, he added.
Remnants of the Taleban, the former regime in Afghanistan carry out attacks in the south and south-east of the country regularly.
Nearly 300 people have been killed, including Taleban fighters, since the beginning of August.
The dead include aid workers, government soldiers and
police, US troops and many guerrillas.
Kandahar province has been the scene of many attacks blamed on the guerrillas.