“It’s not clear if the terrorists attacked from outside, or if they snatched the ammunition from staff inside” while being interrogated following their arrest, Bannu police spokesman Muhammad Naseeb told Reuters.

He said the compound had been surrounded by security forces.

Two other officials, speaking on condition of anonymity, said the militants were looking to negotiate for safe passage to neighbouring Afghanistan.

One said about 15 militants took control of the centre after overpowering interrogators inside, grabbing their weapons and taking five or six of them hostage.

The affiliation of the militants was not immediately known.

Pakistan has been fighting an insurgency by the Tehreek-e-Taliban Pakistan. The TTP associates itself with Afghanistan’s Taliban, which had been trying to broker talks between the Pakistani government and the TTP.

A spokesman for the TTP did not immediately confirm or deny a link with the militants in the compound.

Earlier in the day, at least four policemen were killed and four got injured after militants attacked the Burgi police station in Lakki Marwat.

“Terrorists hurled hand grenades, fired rocket launchers, and sprayed the Bargi Lakki Marwat police station with bullets,” police spokesperson Shahid Khan said and added that more than 60 policemen were on duty when the suspected terrorists descended on the police station at around 12:30am, resulting in an intense exchange of fire with the police.

He said that the policemen engaged the militants for almost 45 minutes after which the attackers escaped, taking advantage of the darkness.