Libya's rebels have accused neighbouring Algeria of "an act of aggression" for allowing Muammar Gaddafi's wife and three of his children to enter the country.
The Algerian foreign ministry has confirmed that Colonel Gaddafi's wife Safiya, daughter Aisha, and sons Hannibal and Mohammed, along with their children, crossed the Algeria-Libya border on Monday.
The Algerian ambassador to the United Nations, Morad Benmehidi, says they were received on humanitarian grounds and no member of the group was on the list of people wanted by the International Criminal Court, the BBC reports.
So far, Algeria has adopted a stance of strict neutrality on the conflict in its neighbour and has not formally recognised the National Transitional Council as the ruling power in Libya.
A spokesperson for the council, Mahmoud Shammam, warned Algeria and other countries against sheltering Colonel Gaddafi and his family and called for their return.
"This is an act of aggression against the Libyan people and their wishes and aspirations. We will use all legal measures to extradite these criminals and put them on trial in Libya, no matter what.
"We warn that anyone trying to shelter Gaddafi and his family will become an enemy of the Libyan people, and we will hunt these criminals anywhere in the world."
The rebels say there are unconfirmed reports that the family has been given a pass by Algeria to enter a third country.
Since the uprising began in February, Colonel Gaddafi has relied more and more on his close family, the BBC reports.
Aisha Gaddafi gave a rousing speech earlier this year, saying her father would not step down, while son Seif al-Islam is his intended successor. Two other sons, Hannibal and Mohammed Gaddafi, are thought to be the least political of all.
But the new political leaders in Libya say the entire family are criminals because they benefited from what many Libyans say was the robbery of their resources and therefore they should all go on trial.
Colonel's whereabouts unknown
Muammar Gaddafi's whereabouts remain unknown since rebels swept into Tripoli last week, capturing his compound.
Italian news agency ANSA, citing Libyan diplomatic sources in Rome, reported that Colonel Gaddafi and two of his sons, Saadi and Seif al-Islam, are in Bani Walid, about 100km south of the capital Tripoli.
Meanwhile, a rebel minister says Colonel Gaddafi's youngest son Khamis, whose death has been announced several times since Libya's conflict erupted but never confirmed, may have been killed south of Tripoli and buried.
The death of the feared military commander has not been independently confirmed.
Rebels advancing on stronghold
Rebels are advancing on a Gaddafi stronghold, the city of Sirte, where thousands of the ousted leader's supporters are thought to be preparing to make a last stand.
The rebels now control most of Libya, after months of clashes. The National Transitional Council's leadership has called for international backers to maintain their military support because they say the "tyrant" remains a threat.
Council head Mustafa Abdul Jalil says NATO and other allies must continue supporting rebels against Colonel Gaddafi, and that his forces could still wage brutal counter-attacks, the BBC reports.