Moamer Kadhafi and his sons Saadi and Seif al-Islam are in the town of Bani Walid south of Tripoli, Italian news agency ANSA said Monday, citing "authoritative Libyan diplomatic sources".
ANSA cited the same sources in Rome saying that Kadhafi's wife Safiya and three of his other children, Aisha, Hannibal and Mohammed were in Algeria.
The Algerian foreign ministry later confirmed the four crossed into Algeria earlier Monday.
ANSA said another Kadhafi son, Khamis, had "almost certainly" been killed on the way from Tripoli to Bani Walid.
Libya's rebel leadership on Sunday said that Khamis, whose death has been announced several times since the conflict erupted, may have been killed in a clash with rebel fighters in the city of Tarhuna southeast of Tripoli.
Bani Walid is about 100 kilometres (62 miles) from the Libyan capital.
Libya's defected former prime minister Abessalam Jalloud, who has fled to Rome, last week said Kadhafi could be hiding south of Tripoli.
"There are two possibilities: either he is hiding south of Tripoli or he left some time ago," Jalloud told reporters.
The leader of the rebel National Transitional Council, Mustafa Abdel Jalil, on Monday cautioned against a let-up in international action against Kadhafi saying he "still poses a danger, not only for Libya but for the world."
"That is why we are calling for the coalition to continue its support," Abdel Jalil said at a meeting of chiefs of staff in Doha of countries militarily involved in Libya.
Italy is Libya's former colonial ruler and enjoyed close diplomatic and economies ties with Kadhafi's regime before the start of a popular uprising this year. It has since joined the international coalition against Kadhafi.
