Islamabad, March 26. (PTI): The police in northwestern Pakistan today tried to prevent a group of suspected militants from delivering a sermon on 'jehad' in a school, triggering a gunfight which left five ultras and a police officer dead.

Armed men barged into a school in Tank near the Afghan border and tried to deliver a sermon on holy war. The police soon arrived on the scene and tried to stop the suspected militants which triggered a gunbattle.

Five militants and a police inspector were killed in the exchange of fire, police said.

Meanwhile, the banned Tehreek Nafaz-e-Sharia Muhammadi (TNSM) outfit has set a 72-hour deadline for the release of its former chief Maulana Sufi Muhammad and threatened suicide attacks all over the country if the demand was not met.

Muhammad was detained some time back for his virulent pro-Taliban speeches and for his efforts to mobilise Pakistani people to fight along with the Taliban in Afghanistan.

Addressing a public meeting in the tribal areas yesterday, TNSM leaders Maulana Abdul Haq, Maulana Dost Muhammad and Maulana Safiullah warned the Government that 100 suicide bombers were ready to hit various targets across Pakistan if Sufi Muhammad was not freed, Daily Times reported.