There have been frequent drone attacks in recent months
A senior Uzbek militant commander in north-west Pakistan is believed to have been killed in a US missile strike in August, intelligence officials say.
Pakistan's interior minister says there is no "conclusive evidence" of his death. But an army source told the BBC that there are "strong rumours".
Tahir Yuldashev was the head of the Islamic Movement of Uzbekistan. A Taliban spokesman denied the report.
Correspondents say many Uzbek militants operate in Pakistan's tribal areas.
Rerports say that Tahir Yuldashev died from his injuries after a drone attack in the Kanigoram region of South Waziristan last month.
His death was first reported on the Radio Liberty station in Pakistan after a man purporting to be his bodyguard rang the station up.
Tahir Yuldashev had been based in South Waziristan close to the Afghan border for some years. He is reported to have fled Afghanistan after the 2001 fall of the Taliban.
If confirmed, his death would be a heavy blow to militant groups operating a long the border.
Correspondents say that his faction had formed alliances with al-Qaeda and the Taliban.
It targeted foreign forces in Afghanistan and carried out attacks Pakistani troops in the tribal belt.
A number of senior militant commanders have been killed in recent missile strikes in the troubled region.
But a Taliban spokesman told the Associated Press news agency that the commander had not been killed.