Hundreds of Pakistani troops battled Islamic insurgents armed with rocket launchers and machine guns in the northwest tribal region near Afghanistan, in a spate of violence that has left at least 42 dead since the weekend, an official said Wednesday. At least three separate skirmishes took place between Pakistani forces and insurgents, a security official said on condition of anonymity. However, it was not immediately clear whether rebels or security forces suffered any fresh casualties in the clashes that began late Tuesday and continued before dawn Wednesday in North Waziristan, where many al-Qaida fighters are believed to have sought refuge. The official gave no other details. Tension has been high in the region since Saturday when insurgents attacked a military post with rockets, killing eight soldiers. The attack came about one hour after an explosion at a local cleric's home near the Afghan border left eight dead. Tribal elders blamed US military for the assault, and Pakistan lodged a protest over the incident with the US-led coalition forces in neighboring Afghanistan. On Tuesday, the Pakistani military said that it killed 14 suspected extremists, blamed for an earlier assault on a military post that left seven soldiers dead. Those killed "included some foreigners and a local commander of the miscreants," the official said, using the term to describe insurgents operating in the area. Pakistan has placed about 70,000 troops and paramilitary forces along its border with Afghanistan to weed out alleged al-Qaida and Taliban sympathizers and extremists. Security officials have said hundreds of Arab, Central Asian and Afghan insurgents - allegedly linked with al-Qaida - are in North and the adjoining South Waziristan. Last month, a senior al-Qaida suspect from Egypt, Hamza Rabia, was killed in the area. Pakistan denied residents' claims that he died in a US missile strike.