ISLAMABAD A U.S. drone strike killed a senior al Qaeda figure in northwest Pakistan after a tipoff from local intelligence, Pakistani intelligence officials said on Saturday.
But a U.S. National Security official in Washington said he could not confirm the report and warned it could be premature.
The elimination of Ilyas Kashmiri, regarded as one of the most dangerous militants in the world, would be another coup for the United States after American special forces killed Osama bin Laden in a garrison town close to Islamabad on May 2.
More cooperation from Islamabad could help repair ties with ally Washington, badly damaged when it was discovered that bin Laden had apparently been living in Pakistan for years.
One Pakistani intelligence official in Islamabad and three in the northwest said Kashmiri had been killed.
"We are sure that he (Kashmiri) has been killed. Now we are trying to retrieve the bodies. We want to get photographs of the bodies," said the Pakistani intelligence official in Islamabad.
Kashmiri was wrongly reported to have been killed in a September 2009 strike by a U.S. drone. It is difficult or impossible to get confirmation of the identities of those killed in drone strikes because they take place in remote areas not accessible to foreign journalists.
A Pakistani television station quoted the group Kashmiri headed, Harkat-ul Jihad Islami (HUJI) which is allied to al Qaeda, as saying the latest report was true.
"We confirm that our Amir (leader) and commander in chief, Mohammad Ilyas Kashmiri, along with other companions, was martyred in an American drone strike on June 3, 2011, at 11:15 p.m.," Abu Hanzla Kashir, who identified himself as a HUJI spokesman, said in a statement faxed to the station.
"God willing ... America will very soon see our full revenge. Our only target is America."
The U.S. National Security official expressed doubts about the statement. Its authenticity could not be independently verified. Britain's Channel 4 News said the death had been confirmed by a senior HUJI commander and close aide of Kashmiri.
Kashmiri, said to be a former Pakistani military officer, and other militants were with an Afghan Taliban member involved in liaison with the Pakistani Taliban when the drone missile struck, said the intelligence official.
He said they were in a house in South Waziristan, close to the Afghan border in northwest Pakistan, that was believed to be the HUJI headquarters of Kashmiri's group, which has been described as an operational wing of al Qaeda.
"We were closing in on him and he switched off his satellite phone and cellphone and he wanted to cross the border to Afghanistan to find a hiding place," the Islamabad official added. "It was a tipoff by us since we were closely monitoring his movements."
Five of his close allies were killed in the attack by a pilotless drone aircraft, intelligence officials said.
U.S. ASKED PAKISTAN TO GO AFTER KASHMIRI
The killing of bin Laden aroused international suspicions that Pakistani authorities had been complicit in hiding him, and led to domestic criticism of them for failing to detect or stop the U.S. team that killed him.
U.S. scepticism of claims of Kashmiri's demise may be further evidence of deep distrust between Pakistani and U.S. intelligence services public pledges by Secretary of State Hillary Clinton and other American officials that relations had improved.
Kashmiri was on a list which Washington gave Pakistan of militants it wanted killed or captured, a Pakistani official said.
Drone strikes have increased under the Obama administration, sometimes killing civilians and fuelling anti-American sentiment.
While Pakistani leaders publicly criticize the attacks, analysts say killing high-value targets would not be possible without Pakistani intelligence.
Washington reiterated its call on Pakistan to crack down harder on militancy after it was discovered that bin Laden had been living in the country.
The U.S. Department of State has labeled Kashmiri a "specially designated global terrorist." He has been linked to attacks including the 2008 rampage through the Indian city of Mumbai which killed 166 people.
The Pakistani media has speculated that Kashmiri was the mastermind of an attack on the PNS Mehran naval base in Karachi last month which humiliated the Pakistani military.
(Additional reporting by Saud Mehsud in Dera Ismail Khan, Hafiz Wazir in South Waziristan, Faisal Aziz in Karachi, Mark Hosenball and Myra MacDonald in London; writing by Michael Georgy; Editing by Jon Boyle)