"There is strong indication" that Pakistani Taliban leader Baitullah Mehsud was killed in a CIA drone strike that targeted a house Wednesday, a senior administration official told ABC News.
U.S. and Pakistani officials believe that a strike in South Waziristan yesterday "very likely" killed Mehsud. U.S. officials said they had visual and other "indicators" that it was Mehsud, and that there is a 95 percent chance that he is among the dead. Pakistani officials are trying to collect physical evidence to be certain.
Baitullah Mehsud is enemy number one in Pakistan. He is believed to be behind some of the most spectacular attacks in that country, including the assassination of Benazir Bhutto in December 2007 and suicide bombings in Lahore. U.S. officials consider him a grave threat and the nexus of all terror groups in Pakistan. In fact, the U.S. had a $5 million reward on his head.
If Mehsud's death is confirmed, the Obama administration would have hit one of the most significant terrorist targets in years. Obama's head of counterterrorism, John Brennan, said the President has made the pursuit of terrorists a priority.
"Over the past six months, we have presented President Obama with a number of actions and initiatives against al Qaeda and other terrorist groups," said John Brennan, Obama's head of counterterrorism.
"Not only has he approved these operations, he has encouraged us to be even more aggressive, even more proactive, and even more innovative, to seek out new ways and new opportunities for taking down these terrorists before they can kill more innocent men, women and children," said Brennan.
The missile attack is also said to have killed at least three people, and Mehsud's second wife is thought by U.S. and Pakistani officials to be among them.
Mehsud's network is based in the remote region of South Waziristan, in northwest Pakistan, where the Pakistani army has little control and which the Taliban and senior members of al Qaeda consider a stronghold. The U.S. and Pakistan have been trying to track Mehsud for months.
Makeen, where Wednesday's strike took place, is Mehsud's birthplace and a town he is said to occasionally visit.
Increased Attacks Have Targeted Taliban Leader
The latest U.S. attack is part of the intensified efforts in the region to target and kill top Taliban leaders. The strike was at least the 29th by an unmanned American drone this year, according to an ABC News tally. Nine of the last 10 drone strikes, since June 23, have targeted Mehsud and his network.
Last month, a CIA drone strike nearly killed Mehsud when it hit a funeral he was attending. Instead, it killed 65 other people.
The Pakistani government has publicly criticized the U.S. attacks, but privately officials acknowledge that if the attacks do not kill civilians, they are helpful in defeating an insurgency embedded in some of the world's least hospitable terrain.
Pakistan has also increased its attacks by fighter jets in the region but has steered clear of sending ground troops.
In an interview with al Jazeera in January 2008, Mehsud said he was fighting a "defensive" jihad against the West.
"Our main aim is to finish Britain, the United States and to crush the pride of the non-Muslims," he told al Jazeera at the time. "We pray to God to give us the ability to destroy the White House, New York and London. And we have trust in God. Very soon, we will be witnessing jihad's miracles."
For Pakistan, the hit could have a profound effect. New commanders would undoubtedly take Mehsud's place, if he is confirmed dead. However, his death would give Pakistan's leaders confidence that the Taliban are not all-powerful and that the leadership can be decapitated.
The blow could also help push Pakistan's people to confront the Taliban in their country -- which the U.S. has said is crucial in defeating the terrorist network in the nuclear-armed nation.
ABC News' Huma Khan contributed to this report.