Helicopter gunships and artillery on Tuesday bombarded two militant hide-outs that had been used to launch attacks on security forces in a troubled tribal region near the Afghan border, the Pakistani army said. Spokesman Maj. Gen. Waheed Arshad said forces targeted a pair of compounds in Daygan, a village about 15 kilometers west of North Waziristan's main town of Miran Shah after receiving "credible intelligence that militants were present there." It appeared to be the army's toughest military action in the lawless border region after a month of escalating violence, and came a day after foreign ministry spokeswoman Tasnim Aslam said al-Qaida and the Taliban had no safe havens in the tribal zone. Cobra helicopter gunships and artillery launched the attack about 5 a.m. and it lasted about four hours, Arshad said. No ground forces were used in the assault, and there was no immediate word on militant casualties. "The militants used to regroup and prepare attacks on security forces and take refuge at these compounds, so security forces targeted them," Arshad told Dawn television, calling the compounds a "staging post." A local security official, speaking on condition of anonymity because he was not authorized to speak to journalists, said the militants had retaliated and both sides had used light and heavy weapons. Residents in Miran Shah could hear the artillery and said a stray mortar struck a home, wounding three civilians, including two children, who had been transported to a hospital in the town. The security official confirmed that some weapons fire had hit a home in Daygan, and that three or four people had been injured. The assault appeared to be the toughest military action since troops that were withdrawn from key checkpoints under a controversial peace deal with pro-Taliban militants in September 2006 were redeployed to North Waziristan about a month ago - prompting militants to pull out of the deal and resume attacks. President Gen. Pervez Musharraf, a key ally of the United States in its war on terror, is under pressure from Washington to crack down on militants after US intelligence agencies concluded that the peace deal had allowed al-Qaida to regroup. Violence has surged in Pakistan, particularly along its northwestern frontier with Afghanistan, since an army raid on Islamabad's pro-Taliban Red Mosque in early July. In all, more than 350 people have died in suicide bombings and clashes between militants and security forces. Pakistan says it has 90,000 troops deployed near the border to combat militancy and attacks on Western and Afghan forces in Afghanistan.