ISLAMABAD, Oct. 21 (Xinhua) -- Three people were killed in a suspected U.S. drone attack in northwest Pakistan's North Waziristan tribal agency as the Pakistani security forces pushed further towards the Taliban strongholds in the abutting South Waziristan, local TV reports said Wednesday.

    The reports said the unmanned aircraft fired missiles at a village in Miranshah of North Waziristan, killing at least three people and injuring more others.

    The United Stated has intensified drone attacks on the tribal regions despite Pakistan's protest at a time when the security forces are engaged in major offensive against Taliban militants in South Waziristan.

    The drone attack came as the ongoing Pakistan's army operation strived forward into the lawless tribal area near the border with Afghanistan, with 18 militants reportedly killed on Wednesday including six foreign militants.

    According to sources, the security forces continued shelling on extremists hideouts in Ladha, Makeen and other adjacent areas of Southern Waziristan.

    The security forces ground troops continued to advance to the key bases of extremists in the region, however in some areas security forces were also facing stiff resistance.

    Local TV reports said the forces have demolished the houses of Taliban chief Hakeemullah Mehsud and suicide attacks mastermind Qari Husain in Kotkai area of Southern Waziristan.

    On the other hand, some extremists attacked an army camp in Razmak area of Northern Waziristan with mortar guns, however no casualties have been reported. 

Special Report: Pakistani Situation