Islamabad - Pakistani security forces imposed a curfew in the volatile north-western valley of Swat Wednesday as pro-Taliban militants targeted security checkpoints and government buildings, officials said.

Violence has resurged in recent weeks in Swat, about 300 kilometres north-west of Islamabad, after Islamist militants resumed attacks on security officials despite a two-month peace agreement.

The round-the-clock curfew would remain in force until further orders, said Major Mohammad Farooq, an Army spokesman in the area.

The curfew was declared after a spate of attacks in which militants blew up a state-owned hotel and an Army guesthouse in Pakistan's only ski resort of Malam Jabba. The abandoned hotel was also torched last month.

A school for girls and several key bridges in other towns were also destroyed by homemade bombs.

Media reports said clashes had intensified between government troops and militants in the valley's Matta subdistrict after the curfew was imposed.

No casualty figures were immediately available. However, a spokesman for the Pakistani Taliban active in the area claimed the militants destroyed an armoured personnel carrier, killing several soldiers, but Farooq denied the claim.

Scores of rebels on Tuesday seized more than two dozen police and paramilitary troops after laying siege to a security check post in the town of Kabal. The kidnappings came a day after militants gunned down three intelligence officers at a roadblock.

The military launched a crackdown on armed supporters of a firebrand cleric in Swat in November and the operation continued until March when the new government initiated peace talks with the guerillas, bringing a brief lull in the violence.

A fragile ceasefire was reached in May, but the militants kept carrying out sporadic attacks on security forces amid claims that the military was violating the accord. (dpa)