Militants have attacked a prison in northwestern Pakistan, in an apparent attempt to free jailed Taliban and al-Qaida terrorists.
Witnesses say security forces are engaged in a firefight with the attackers at the prison in the town of Dera Ismail Khan. An intelligence official says the militants can be heard shouting "Long Live the Taliban."
Residents living near the prison say they heard several large explosions before the attackers opened fire with machine guns and grenades.
As many as 250 convicted terrorists are believed to be held in the prison.