At least four suspected militants were killed and seven others were injured in a U.S. drone strike on Saturday morning in Pakistan's northwestern tribal region bordering Afghanistan, local media reported.

According to local Urdu TV Dawn News, the U.S. pilot less plane fired four missiles at a suspected compound belonged to militants in Bermal area of South Waziristan, one of Pakistan's northwestern tribal regions bordering Afghanistan.

Local people told media that the two drones strike the house at 02:30 a.m. (local time) in the Baghareecha area of Sub-district Bermal.

The identities of the killed or injured people were no immediately known.

It is the fourth U.S. drone strike in Pakistan's Waziristan tribal region in last three days.

On Friday, the drone fired hit a house and vehicle at the Darpakhel area of the North Waziristan and killed four suspected militants.

On Thursday, U.S. spy planes carried out two strikes in North and South Waziristan and had reportedly killed 7 suspected militants including a commander of the Haqqani network.

Pakistani and the U.S. security officials have confirmed the death of Janbaz Zadran also known as Jamil. He was the lieutenant of Badruddin Haqqani, brother of Sirajuddin Haqqani, leader the group.

Pakistani media reported that Jamil was in-charge of the logistic affairs of the Haqqani network but he was not member of the Haqqani family.

Local tribesmen said that members of the Haqqani network had been living in Dande Darpakhel area for years but all had left the region as the result of military operation in 2005.

Jalaluddin Haqqani, a former Afghan Jehadi commander and father of Sirajuddin Haqqani, had established religious schools in the area during the 1979-89 Soviet invasion of Afghanistan.

Pakistan is under U.S. pressure to launch major operation against the Haqqani network, blamed for the last year two attacks on U.S. embassy in Kabul and a truck bomb attack on an U.S. military base in Maidan Wardak province.

The U.S. has again stepped up drone strikes amid tension between the United States and Pakistan over Haqqani network. But some analysts believed that the sharp increase in the drone attacks showed that the two countries have revived intelligence sharing.

Top U.S. military leaders insisted that Pakistan has links with the Haqqani network and supported the group in their two attacks in Afghanistan on the U.S. embassy and a military base last month. Pakistan dismissed the charges as irresponsible.

The U.S. Secretary Defence Leon Panetta had threatened unilateral action against Haqqani network and other Pakistan-based extremist groups after the Taliban attacked the U.S. embassy in Kabul on Sept. 13.

Panetta had said that Pakistani intelligence had supported the militants in the embassy attack and also a truck bomb attack on the U.S. military base at Maidan Wardak province of Afghanistan on Sept. 11. Pakistan had rejected the threats as contrary to the spirit of cooperation in the war on terrorism.