Government troops backed by helicopter gunships repelled an attack on a military checkpoint in northwestern Pakistan on Tuesday, killing up to 12 militants, an army spokesman said.

Up to 40 militants attacked the checkpoint near Miran Shah, the main town in the North Waziristan tribal district, army spokesman Maj. Gen. Waheed Arshad said.

"Our forces retaliated and returned fire, and destroyed their vehicles," Arshad said. "According to the reports I have received, between 10 to 12 miscreants were killed."

No soldiers were killed or wounded in the midmorning attack, he said.

Violence has surged across Pakistan since a bloody military raid three weeks ago to oust radical clerics and their followers from Islamabad's Red Mosque.

Most of the violence has been in the tribal belt along the border with Afghanistan. More than 300 people have died since July 3.

President Gen. Pervez Musharraf, a key U.S. ally in the fight against terrorism, has come under increasing pressure from Washington to do more to combat Taliban and Al Qaeda fighters in the tribal zone.

Rebels have stepped up attacks against security forces in North Waziristan in the past two weeks after scrapping a September 2006 peace deal with the government.

To the north, about 70 pro-Taliban militants seized control of a shrine and mosque in Mohmand, another tribal region, on Sunday and renamed it after the Red Mosque. Local officials on Tuesday sought the support of tribal elders to persuade them to leave without bloodshed.

In Islamabad, about 2,000 women demonstrated outside Islamabad's sprawling Faisal Mosque on Tuesday urging the government to enforce strict Islamic law.

"The blood for the martyrs of Red Mosque ... will not go to waste!" the demonstrators chanted.

In other violence in the northwest, a roadside bomb wounded six security force members driving near the northwestern town of Tank, said Zarin Mumtaz, a local police official. The army confirmed the attack and the casualties.

Near Miran Shah, suspected militants fired eight rockets before dawn at three military checkpoints, damaging a school dormitory nearby but causing no injuries, said a security official who sought anonymity because he was not authorized to speak to media.

Near Bannu, about 30 miles east of Miran Shah, militants kidnapped four paramilitary forces and their vehicle, two local security officials said on condition of anonymity because they were not authorized to speak to journalists. Officials were trying to secure their release.