Libyan officials say they will delay the burial of ex-leader Moammar Gadhafi as they investigate the circumstances of his death Thursday in his hometown Sirte. The United Nations Human Rights Commission is among those calling for a probe.

Questions of how and by whom Gadhafi was killed intensified Friday, even as many Libyans continued to celebrate that, no matter by what means, the longtime leader was gone and another milestone in their country's transformation had been reached.

Fighters in Misrata chanted that "the blood of the martyrs will not be in vain" while others expressed their relief and joy at the developments in gatherings after Friday prayers.

Video, images of capture 

More video emerged that appears to be of the moment Gadhafi was captured alive. Other images from later in the day show him lying apparently lifeless on the ground, surrounded by angry men.

Officials have given differing accounts of how he died, with the interim prime minister Mahmoud Jibril saying he was shot in the head during crossfire on the way to a hospital. Others say he died of his initial wounds while on route, while the most widely circulated versions have him kicked and killed by his captors.

U.N. human rights spokesman Rupert Colville said Friday the video evidence is disturbing. Speaking in Geneva, he added there should be an investigation to see if he was killed in fighting or executed after his capture.

"Summary executions are strictly illegal under any circumstances. It's different if someone is killed in combat," Colville said. "There was a civil war taking place in Libya, so if the person died as part of the combat, that's a different issue. That's normally acceptable in the circumstances. But if something else has happened, someone is captured and then deliberately killed, that's a very serious matter."

What to do with remains 

There was also debate about what to do with Gadhafi's remains. By Islamic custom, he should be buried as quickly as possible, although several officials say that an investigation will have to be carried out before that can happen. Officials are also said to be undecided on where his grave should be, with some arguing for a secret burial.

The former leader's body was initially taken to a mosque in Misrata. Authorities say it is now being held there in cold storage until they can decide on the next step.

Gadhafi's son 

The body of his son Muatassim Ghadafi, also killed Thursday, was on public display in the same town.

Gadhafi and several members of his family and inner circle were attempting to flee Sirte Thursday when a NATO strike hit the convoy. Gadhafi managed to escape and apparently took refuge in a drain pipe nearby.

NATO, working under a U.N. mandate, played a key role in helping the new government come to power. The alliance is now winding down its operations.

Libyan officials say that after the events of Thursday they are ready to declare Libya liberated. Authorities are expected to announce plans for the next steps in the political process at a news conference Saturday.