Two missiles believed to have been fired by a U.S. drone aircraft struck a militant hideout, killing six fighters in Pakistan's South Waziristan tribal region on Thursday, intelligence officials said.
Pakistani Taliban chief Baitullah Mehsud was killed in a similar attack in the same region on Aug. 5.
The Taliban had been in denial for weeks about Mehsud's death, but on Monday two of his aides, Hakimullah Mehsud and Wali-ur-Rehman, confirmed their leader had been killed.
Thursday's was the fourth such strike by pilotless U.S. drones this month, and the first after Hakimullah, who led militants in Orakzai, Khyber and Kurram tribal regions, was picked as the new overall commander of the Pakistani Taliban.
Here are some facts about the U.S. missile attacks, the controversy they have caused, and a list of some of the more prominent militants killed, according to Pakistani officials.
WHY DOES THE UNITED STATES ATTACK?
Many al Qaeda members and Taliban fled to northwestern Pakistan's ungoverned ethnic Pashtun belt after U.S.-led soldiers ousted Afghanistan's Taliban government in 2001. From their sanctuaries there, the militants have orchestrated insurgencies in Afghanistan and Pakistan. The United States and Afghanistan have pressed Pakistan to eliminate the sanctuaries. Apparently frustrated by Pakistan's inability to do so, the United States is hitting the militants itself.
HOW MANY ATTACKS?
The United States has carried out about 53 drone air strikes since the beginning of last year, most since September. The death toll stands over 480, including many foreign militants, according to a tally of reports from Pakistani intelligence agents, district government officials and residents.
U.S. attacks on Pakistani Taliban leader Mehsud and his men in South Waziristan picked up after the Pakistani government ordered a military offensive against him in June.
WHERE ARE THE DRONES LAUNCHED FROM?
A senior U.S. lawmaker, Senator Dianne Feinstein, told a U.S. Senate hearing in February that the drones were being operated and flown from an air base inside Pakistan. Pakistan denied that, saying no permission had ever been issued for the strikes.
Although its military has also bombarded Mehsud's stronghold with air raids and artillery, Pakistan officially objects to the U.S. drone strikes, saying they violate its sovereignty.
Pakistan also worries the strikes could undermine efforts to deal with militancy because the civilian casualties they cause inflame public anger and bolster support for the fighters.
Pakistan has pressed the United States to provide it with drones to allow it to conduct its own anti-militant operations.
The United States has shrugged off Pakistani protests. It says the missile strikes are carried out under an agreement with Islamabad that allows Pakistani leaders to decry the attacks in public. U.S. officials said in May that Washington had given Pakistan data on militants in the Afghan border area gathered by surveillance drones in Pakistani airspace under an agreement with Pakistan.
SOME OF THE PEOPLE REPORTED KILLED
Jan. 28, 2008 - A senior al Qaeda member, Abu Laith al-Libi, was killed in a strike in North Waziristan.
July 28 - An al Qaeda chemical and biological weapons expert, Abu Khabab al-Masri, was killed in South Waziristan.
Nov. 22 - Rashid Rauf, a Briton with al Qaeda links and the suspected ringleader of a 2006 plot to blow up airliners over the Atlantic, was killed in an attack in North Waziristan. An Egyptian named as Abu Zubair al-Masri was said also killed.
Jan. 1, 2009 - A U.S. drone killed three foreign fighters in South Waziristan, Pakistani agents said. A week later, a U.S. counter-terrorism official said al Qaeda's operational chief, Usama al-Kini, and an aide had been killed in South Waziristan. The U.S. official declined to say how or when they died.
Aug. 5 - U.S. drones fired missiles into Baitullah Mehsud's father-in-law's house. Pakistani and U.S. officials said Mehsud was killed in the strike, while Taliban said he was seriously wounded in the attack and died on Sunday.