Police rush to the scene of a suicide blast in the Pakistani city of Peshawar on Monday.

At least four people were killed in the attack on a judicial compound.

Officials said one bomber blew himself up outside the complex, causing the carnage.

The other entered the complex, attempting to release militants jailed inside, officials said.

He took hostages and but was shot dead by security forces.

There was no immediate claim of responsibility.

Taliban militants, who are close to al Qaeda, are fighting to topple Pakistan's U.S.-backed government.

They have targeted the military, security forces and civilians.