MINGORA, Pakistan, Oct 31 (Reuters) Islamist militants fired at helicopter gunships flying over their northwest Pakistan stronghold today, officials said, as violence that has killed scores since last week resumed after a brief truce.
In separate incidents overnight, pro-Taliban militants fired rockets at a police station in the Swat valley in North West Frontier Province, while four civilians were killed in crossfire in a tribal area further north, witnesses said.
Militants led by pro-Taliban cleric Maulana Fazlullah, who is seeking to impose strict Islamic code in Swat, told residents in the village of Matta -- their stronghold -- to leave their homes, raising fears fighting could deepen.
''Militants violated the ceasefire and our forces retaliated,'' said a senior paramilitary official who asked not be named.
Helicopter gunships opened fire and troops also fired artillery.
There were no immediate details of any damage or casualties.
Swat, a scenic valley close to Pakistan's lawless tribal belt bordering Afghanistan, has seen a surge in militant activity since Fazlullah launched an illegal FM radio and urged a holy war.
The government has sent in around 2,000 troops to quell growing militancy in the area.
Fighting was triggered on Thursday when a suicide bombing targetting an army convoy killed 21 people. Militants then executed 13 people the following day, including six members of the security forces whom they beheaded.
Fighting, which has killed around 100 people since last week, came to a halt on Monday after the militants called a truce to bury the dead.
In a separate incident, four civilians were killed in the North Waziristan tribal region during an exchange of fire between the security forces and militants yesterday, witnesses said.
''A mortar bomb hit a hotel in Miranshah and killed four people,'' local resident Mohammad Khan said, referring to North Waziristan's main town. Both North and South Waziristan are hotbeds of support for Taliban and al Qaeda militants who fled Afghanistan in late 2001.
Violence has escalated across Pakistan since July, when militants scrapped a peace deal and the army stormed a radical mosque in the capital, Islamabad, to flush out pro-Taliban militants.
A suicide attack killed at least seven people, including the bomber, yesterday less than a kilometer from Pakistan President Pervez Musharraf's army residence in the garrison town of Rawalpindi near Islamabad.
That attack in turn came a fortnight after a suicide attack killed 139 people at a rally to mark the return of former prime minister Benazir Bhutto after eight years of self-imposed exile to avoid graft charges.
REUTERS ARB PM1815