The death toll of the Wednesday morning's U.S. drone strike in Pakistan's northwest tribal area of North Waziristan has climbed up to 25, said sources of Xinhua in the region.

A correspondent in Miranshah, center of North Waziristan, told Xinhua on phone that all the people killed in the strike were members of the Haqqani network, a terrorist group led by Afghan leader Sirajuddin Haqqani.

The U.S. and Afghan officials blame the Haqqani network for planning cross-border attacks from North Waziristan into Afghanistan on the U.S.-led NATO forces and Afghan forces.

The correspondent, requesting not to be identified, said that eight other militants were also injured in the strike and they had been transferred to a main hospital in Miranshah. All the injured are in critical condition, said the correspondent who visited the hospital.

He said that in the wee hours of Wednesday, the U.S. drone fired two missiles on a compound at Kharunai, a small village just one kilometer from Miranshah, when the militants were having pre- dawn meal or "Sehri" in the Muslim month of Ramadan.

Other militants, both Afghans and Pakistanis, arrived at the scene after the drone left the area and they pulled out the bodies and the injured from the rubbles of the destroyed compound, said the correspondent, adding that they did not allow local tribesmen to reach the site.

Wednesday's strike is one of the deadliest in years as many militants were killed in a single strike in Waziristan region which the United States considers as the main base for al-Qaida and Taliban militants.

Security sources said that the militants had arrived at the compound late Tuesday night and were having night stay there.

Pakistan is under mounting U.S. pressure to launch major operation against the foreign and local militants in North Waziristan.

North Waziristan borders Afghanistan's three eastern provinces, namely Khost, Paktiya and Paktika where fighters of the Taliban- affiliated Haqqani network are active.

The network is named after Jalaluddin Haqqani, former Jeahdi leader who also served minister in Taliban regime. Haqqani's son Sirajuddin is now heading the group.

The fresh strike came at a time when the relations between the United States and Pakistan are thought to be at lowest ebb. Pakistan publicly opposes drone strikes in its tribal regions, terming it as counterproductive in the war against militants.

CIA and the top U.S. defense officials have ruled out any change in the drone strike policy.

U.S. officials insist that drone strikes are effective in the on-going war against the militants as several key al-Qaida and Taliban leaders including founder of the Pakistani Taliban movement Baitullah Mehsood have been killed in these attacks. However, Pakistani tribesmen say that the majority of the victims of drone strikes are locals.