Lahore, Jan 7: Pakistani security officials believe that a single assassin with a gun and a bomb killed former Prime Minister Benazir Bhutto.

They concluded that a man fired at least three shots at Benazir and detonated a bomb seconds later.

According to The Observer, one of the principal pieces of physical evidence was assassin’s severed head, adding that plastic surgeons had reconstructed the face and printed the picture in two national newspapers, offering Rs 10 million to anyone identifying him.

The paper quoted a police officer as saying that he had started running towards the gunman when he saw him raise his arm.

"He got there just too late, and he saw him lower his head just before the blast," a source said.

"That is what the suicide bombers have been told to do to obliterate their features." In this case, however, the tactic appeared to have failed, The Observer said.

The paper said that a second man with a beard and shawl, captured in pictures of the assassination, turned out to be an innocent bystander.

The government was sticking to its assertion that the assassination was carried out on the orders of Taliban commander Baitullah Mehsud, it added.

"US and British officials have said that an intercepted satellite telephone conversation in which Mehsud offers congratulations to a fellow militant for the killing appears credible," the paper said.

The investigators had cross-checked thousands of calls made from the area around the assassination site in the run-up to the killing against lists of numbers used by suspected jihadis, leading to at least two arrests.

However, there were still conflicting accounts of the cause of death, even within the current caretaker government, the paper said.

The Observer quoted a Western official with extensive security expertise in Pakistan as saying that he believed "conclusively" that Benazir was killed by the blast from the bomb and not by an assassin’s bullet. "

"I do know the shots didn’t hit her. The Interior Ministry allowed me to be party to photos and other materials that showed it wasn’t a bullet," the official said. (ANI)