Najmiddin Jalolov, also known as Yahyo, was killed on Monday when a pilotless US drone aircraft fired a missile at a truck near the town of Mir Ali, which has for years been known as a militant sanctuary, the officials said.

"He was among three top militant commanders from central Asia who had an affiliation with al Qaeda and had been working in and from our territory," said a senior Pakistani intelligence official, who declined to be identified.

A second Pakistani security official said Jalolov was among four militants killed in the strike, the report said.

Jalolov was the founder of a militant group called the Islamic Jihad Union, the Pakistani officials said.

The US Treasury banned US dealings with Jalolov and tried to freeze his assets in June last year, saying he was an organiser of suicide bombings in Tashkent in 2004 that killed at least 47 people, the report noted.