Libya's provisional government leaders are preparing to formally declare the country liberated, following Thursday's capture and death of former leader Moammar Gadhafi.

News reports say the National Transitional Council will make the declaration on Saturday or Sunday in Benghazi, the eastern city that became the hub of the anti-government movement.

Meanwhile, NTC officials are trying to determine when and where to bury Gadhafi.

On Friday, his body laid on display on a mattress in the freezer of an old meat store in Misrata.

Some visitors used their mobile phones to take pictures of the dead leader. Video of Gadhafi's body shows what appears to be a bullet hole in the left side of his head and another in the center of his chest.

Uncertainty over how Gadhafi met his end has raised the possibility of an investigation by the International Criminal Court at The Hague. The United Nations and rights groups have questioned how he died.

U.N. human rights office spokesman Rupert Colville said Friday the circumstances surrounding Gadhafi's death were “unclear” and that videos showing his demise were “disturbing.”

Mobile phone video shows National Transitional Council fighters carrying a wounded and bleeding Gadhafi shortly before he died. Later images showed his body with apparent gunshot wound to his head.

Interim Prime Minister Mahmoud Jibril said an autopsy had been done and that results and samples were being sent to the ICC.

Earlier, he had said Gadhafi was pulled from a hiding place in a sewage pipe and later mortally wounded in crossfire between pro- and anti-Gadhafi fighters.

Other officials said he was beaten and then killed.

Also Friday, Gadhafi's wife joined those calling for an investigation. Syria-based Arrai Television quoted Safia Gadhafi as demanding the U.N. probe how he died.

In another development, NATO officials meeting in Brussels on Friday agreed to end their mission in Libya. NATO Secretary General Anders Fogh Rasmussen said alliance members made a preliminary decision to end air operation on October 31.

Gadhafi had ruled Libya for more than four decades when a rebellion began in Benghazi in February and then spread across the country.