WASHINGTON, Oct 2 (Reuters) - U.S. intelligence agencies believe the newly named leader of the Taliban in Pakistan, Hakimullah Mehsud, might have been killed in a firefight with a rival faction weeks ago, officials said on Friday.Militants tapped Hakimullah to replace the group's previous leader, Baitullah Mehsud, who was killed by a missile fired from a CIA-piloted drone aircraft in his South Waziristan stronghold on the Afghan border on Aug. 5.
Hakimullah's death, which officials said has yet to be confirmed definitively, would be another setback for a group that has mostly been fighting against Pakistani security forces but also sends militants to join the battle against U.S. and NATO forces in neighboring Afghanistan.
"We're pretty clear that we think he's dead," a U.S. defense official said of Hakimullah.
A counterterrorism official said: "While there's no final confirmation of his death, it's a distinct possibility."
The officials, who spoke about the intelligence on condition of anonymity, said Hakimullah was believed to have been shot weeks ago during a clash with a rival group in South Waziristan.
U.S. intelligence agencies are still reviewing information to make a final call on his death.
Washington believes the Taliban has been weakened by infighting between factions vying to take command since Baitullah Mehsud's death.
"The point is there is a succession crisis going on," the defense official said, adding there were other contenders to lead the movement. "There's a variety of factions within the Mehsud tribe."