began moving out through the tunnel at 11 p.m. local time and finished at about 3 in the morning.

The tunnel passed underneath the main Kandahar-Kabul highway to a house at the other end.

NATO officials declined to comment about how many of the escapees are considered Taliban leaders, but Afghan officials are concerned that many seasoned fighters may now return to the war. Since last summer's American troop surge into Southern Afghanistan, hundreds of Taliban fighters and commanders have been killed or captured. Most of them are turned over to Afghan authorities and kept in prisons such as the one in Kandahar.

The highest-profile Taliban inmates would most likely not be held at the 1,200-inmate Sarposa prison. The U.S. keeps detainees it considers a threat at a facility outside Bagramprotected by a ring of concrete barriers topped with razor wire. The entrance can be reached only by passing through multiple checkpoints and gates.

Government officials corroborated parts of the Taliban account of the escape. They confirmed the tunnel was dug from a house within shooting distance of the prison and that the inmates had somehow gotten out of their locked cells and disappeared into the night. Kandahar remains relatively warm even during winter and the ground would not have frozen while insurgents were digging the tunnel.

Police showed reporters the roughly hewn hole that was punched through the concrete floor of the prison cell. The opening was about 3 feet in diameter, and the tunnel dropped straight down for about 5 feet and then turned in the direction of