A battle between Pakistani security forces and suspected Islamic terrorists firing rockets and assault rifles has left 21 dead near the Afghan border, where violence has claimed over 40 lives since the weekend. The latest casualties came Tuesday, when terrorists fired rockets at a mountaintop military post at Sarbandki village in remote North Waziristan, the official said on condition of anonymity in line with policy. Troops returned fire, and the fighting continuing intermittently for several hours. Fourteen suspected terrorists and seven government soldiers were killed in the clash, the official said. The fighting was the latest in a spate of violence that has wracked the rugged, mountainous region in northwestern Pakistan. Four clashes since Saturday have left 42 people dead. The toll includes eight killed in a purported air strike on a house owned by a Muslim cleric. 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. Also Saturday, assailants in South Waziristan ambushed and killed a pro-government tribal elder and four of his relatives, including a 5-year-old girl. At least 60 tribal elders have been killed since they began cooperating with Pakistan's army following the Sept. 11, 2001 attacks in the United States.