Pakistani officials say paramilitary forces backed by helicopter gunships have killed at least 30 Taliban militants, including a commander and five deputy commanders, in a northwestern district.

The officials say Sunday's offensive targeted suspected Taliban bases in Lower Dir district, which is part of the Malakand division of North West Frontier Province. They say the operation began after militants opened fire on a convoy of the paramilitary Frontier Corps, wounding four soldiers.

The region, which includes Swat Valley, is part of a controversial peace deal between the government and militants to impose strict Islamic law (Sharia) in Malakand in exchange for an end to extremist violence there.

But officials say that Taliban militants have violated terms of the Swat deal by exporting fighters to neighboring areas including Buner district, which is just 100 kilometers from Islamabad.

Chief of the federal interior ministry, Rehman Malik, said militants in the region have no option but to disarm.

The Taliban's steady advance toward Islamabad has raised questions in Washington about the ability of the Pakistani army to confront the militants.

But an army spokesman (Major-General Athar Abbas) called these concerns "unfounded." He said that some of the Taliban activity has been exaggerated and that the military is capable of tackling the threat posed by the militants.