ISLAMABAD, Pakistan - U.S. missile attacks on suspected militants in Pakistan's northwest near Afghanistan are undermining the war on terror and "helping the terrorists," the Muslim nation's Foreign Ministry said Friday.

The comments came as a suicide bomber attacked an anti-insurgent group in a northwest tribal area, killing at least 22 and wounding around 100 people. The Orakzai area tribesmen had gathered to plan the demolition of a militant base.

Al-Qaida and Taliban fighters have established bases throughout Pakistan's semiautonomous tribal regions, where they are said to plan attacks on U.S. and NATO forces in Afghanistan as well as violence in Pakistan.

Washington has pushed Pakistan to eliminate such insurgent sanctuaries.

Pakistan has carried out military offensives against insurgents while also trying to woo various tribes to turn against the extremists. Some pro-government tribes have set up militias to fight insurgents.

But in a sign of U.S. impatience with Pakistani efforts, American forces have stepped up their own cross-border assaults on alleged militant targets.

The U.S. is suspected in at least 11 missile strikes on the Pakistan side of the Afghan border since mid-August, killing more than 100 people, most of them alleged militants, according to an Associated Press count based on figures provided by Pakistan intelligence officials.

The United States rarely confirms or denies the attacks, which Pakistan's military and civilian leaders have criticized as violations of the country's sovereignty.

"We want them (the United States) to realize that these attacks are destabilizing the situation, and they are not helping them or Pakistan," Pakistan foreign ministry spokesman Mohammed Sadiq told The AP. "They are helping the terrorists."

The strikes are unpopular among many Pakistanis and used by critics and Muslim conservatives to rally support in their campaign to unseat the country's broadly secular, pro-U.S. government.

The most recent alleged U.S. attack took place late Thursday in North Waziristan and killed at least nine people, between six and eight of them suspected foreign militants, intelligence officials said. They said they were trying to establish the identities of the victims.

The tribal regions also are considered potential hiding places for al-Qaida leader Osama bin Laden, his deputy Ayman al-Zawahri and other non-Pakistani militants.

Friday's suicide attack occurred in Orakzai, a tribal region near the main northwest city of Peshawar that has been relatively peaceful.

Some 500 people of the Alikhel tribe, which has set up a militia to fight insurgents, were gathered when the attacker struck. The tribesmen intended to destroy a major militant base, said Sher Akbar Khan, a government official.

"Initial reports suggest that the suicide bomber rammed an explosive-laden vehicle into the gathering," Khan said.

He said 17 people died at the scene or at a nearby hospital. Walayat Khan, an official at another hospital nearby, said five people died there. A senior government official, Kamran Zeb Kahn, said around 100 people were wounded in the blast, many of them critically.

Prime Minister Yousuf Raza Gilani condemned the suicide attack in a statement.

Also Friday, government official Jamil Ahmad accused militants of beheading four pro-government tribal elders Thursday in Bajur tribal region, the scene of the some of the heaviest fighting between Pakistani troops and insurgents.