A US-led drone strike killed at least four suspected militants in the Waziristan tribal area in northern Pakistan, said security officials Saturday. According to these officials, the attack occurred at a compound in the Heso Khel village near Miranshah tribal region, killing four suspected militants. The drone strikes are very unpopular in Pakistan. Prime Minister Nawaz Sharif has protested against them, declaring them a violation of Pakistan\'s sovereignty. However, Washington considers the drone strikes as vital in the war against terrorism.