Pakistani military airstrikes killed 64 suspected militants in its northwest tribal area near the Afghan border on Thursday, including dozens at a seminary where Taliban commanders were believed to be meeting, officials said.

The jet fire rained in two spells during the day in the Mamuzai area of Orakzai, a tribal region where many Pakistani Taliban leaders are believed to have fled to avoid an army ground offensive further south.

Two intelligence officials said the seminary was a main center for Tableeghi Jamaat, a non-violent Islamic missionary group. They spoke on condition of anonymity because they were not authorized to speak to reporters.

The center was targeted because a group of Taliban leaders were believed to be meeting there in the afternoon. Some four dozens people died in the airstrikes in and around the seminary, while 13 others were killed in morning strikes at the two other sites.

The officials said all 64 were suspected militants. Independent confirmation of the death toll or the victims' identities was nearly impossible because access to the tribal region is restricted.

Meanwhile, local officials told Xinhua that an important Taliban commander Mian Gul was also arrested in Storikheil area of Orakzai during the ongoing operation.

On Wednesday, Pakistani armed forces killed 21 terrorists in Orakzai when they attacked the forces. A security man was also injured in the attack.

Meanwhile, reports suggested that the security forces have also taken control of Shananak mountain in the area.

The operation began hours after a U.S. drone aircraft fired two missiles into a compound in the North Waziristan tribal area near the Afghan border, killing at least six suspected militants.

Pakistani paramilitary troops began operations after midnight Wednesday to flush out militants from the outskirts of the main town in the Orakzai tribal district.

Orakzai is considered a major base for Hakimullah Mehsud, the Pakistan Taliban's top commander, who is believed to have died in a U.S. missile strike in January. The Taliban have denied his death, but have failed to show evidence he is still alive.

The Pakistani Taliban have been under pressure in their main stronghold, South Waziristan tribal region, since the army launched its ground offensive there in October. Many are believed to have scattered to other parts of the tribal belt, which borders Afghanistan in Pakistan's northwest.

Orakzai and neighboring tribal area Kurram have witnessed numerous airstrikes over the past few months as Pakistan tries to catch fleeing militants.

The Orakzai Agency, a valley part of Pakistan's Federally Administered Tribal Areas (FATA), is flanked by 6,000 to 7,000 feet (2,100 m) high mountain ranges, which is attractive for pro Al-Qaeda militants and proved as natural castles for them.

The United States allegedly said that the Taliban and Al-Qaeda militants are creating problems in establishment of peace and offering resistance to the U.S.-led forces in Afghanistan, which is why the U.S. enhanced drone attacks in Pakistan's tribal belt. Nearly 100 U.S. drone strikes have killed more than 830 people in Pakistan's tribal areas since August 2008.