There are reports hundreds of fighters captured in the siege of Kunduz have been killed in a prison riot.
A spokesman for the Northern Alliance says the fighters staged a riot at the prison outside the northern town of Mazar-e-Sharif.
He claims they broke down the doors and tried to escape, and have been battling all day with guards.
Explosions have been heard at the Qalai Janghi fortress, which is under the control of the Northern Alliance.
A German television crew was at the fortress earlier. A translator said the Taliban had seized some weapons from guards and a battle had then broken out.
"It was total chaos there," said the translator.