Libya's rebels are demanding Algeria return Muammar Qaddafi's wife and three of his children for trial after they fled, raising tensions between the two countries.

Mahmoud Shammam, information minister for Libya's interim government, said Algeria's decision to host members of the Qaddafi clan is an "aggressive act against the Libyan people's wish."

Safiya Qaddafi, her daughter Aisha, and sons Hannibal and Mohammad, entered Algeria on Monday, while Qaddafi and several other sons remained at large.

"We are determined to arrest and try the whole Qaddafi family, including Qaddafi himself," Shammam said late Monday. "We'd like to see those people coming back to Libya."

Rebel leaders said they were not surprised when Algeria welcomed Qaddafi's family. Throughout Libya's six-month uprising, the rebels have accused Algeria of providing Qaddafi with mercenaries to repress the revolt.

But Libya's new leaders, trying to make order out of choas, with a fractious, piece-meal army, are in no position to make ultimatums - especially as fighting continues and Qaddafi remains at large.

Qaddafi Really There?

Rebel fighters backed by an escalating Nato bombing campaign are converging on Qaddafi's hometown of Sirte, his last major bastion of support in largely rebel-controlled Libya, amid speculation the longtime Libyan leader might be hiding there.

Sirte, some 400km east of Tripoli, is heavily militarised and shows no signs yet of surrendering. Rebels say they are trying to negotiate a takeover to avoid raging battles in the streets of the city, whose entrances have reportedly been mined, but are willing to launch a major assault if need be - with Saturday as the deadline for surrender.

Nato reported hitting 22 armed vehicles, three command and control sites, four radar installations and several other targets in the Sirte area Monday. Other targets were hit in contested regions south of Sirte.

A Nato officer, who asked not to be identified because of alliance rules, said on Monday there was fighting 50km east of Sirte. He said there are still clashes around Sirte, Bani Walid south of Misrata and Sebha further south.

In Tripoli, rebel leaders trying to set up a new government struggled with widespread shortages of water and fuel. In one neighborhood in the capital, dozens of motorists broke into a gas station Monday and filled plastic contains with fuel. Long lines formed at other gas stations.

50,000 Dead

The rebel deadline for Qaddafi loyalists to surrender comes as the first estimates for the number of dead in Libya's civil war begin to trickle out.

"About 50,000 people were killed since the start of the uprising," Colonel Hisham Buhagiar, commander of the anti-Gaddafi troops who advanced out of the Western Mountains and took Tripoli a week ago, told Reuters.

"In Misrata and Zlitan between 15,000 and 17,000 were killed and Jebel Nafusa (the Western Mountains) took a lot of casualties. We liberated about 28,000 prisoners. We presume that all those missing are dead," he said.

"Then there was Ajdabiyah, Brega. Many people were killed there too," he said, referring to towns repeatedly fought over in eastern Libya.

The figures included those killed in the fighting between Gaddafi's troops and his foes, and those who have gone missing over the past six months, he said.