Update at 2:47 p.m. ET: Libyan rebels call Algeria's sheltering of the Gadhafi family an act of aggression and say they will seek their extradition, Reuters reports.

"We have promised to provide a just trial to all those criminals and therefore we consider this an act of aggression," says Mahmoud Shamman, spokesman for Libya's National Transition Council, according to Reuters.

"We are warning anybody not to shelter Gadhafi and his sons. We are going after them in any place to find them and arrest them," he said.

Update at 1:40 p.m. ET: Al-Jazeera notes that Algeria is one of the few countries that has not recognized the National Transition Council of Libya as the legitimate leadership of the country.

Update at 1:33 p.m. ET: The Algeria Press Service reports that the Foreign Ministry statement states that the U.N. secretary-general and the head of the Libyan National Transition Council have been officially informed of the arrival on Algerian soil of the Gadhafi family members.

Update at 1:21 p.m. ET: The Associated Press confirms the report, also quoting Algeria's state news agency.

The report cites the Foreign Affairs Ministry as saying the family entered the neighboring country Monday.

It did not immediately provide additional details or say whether Gadhafi himself was with the family.

Original report: The Algerian government has confirmed that Libyan leader Moammar Gadhafi's wife and two of his sons have crossed the border into Algeria, Al Arabiya reports.

"The wife of Moammar Gadhafi, Sofia, his daughter Ayesha, and sons Hannibal and Mohammad, accompanied by their children, entered Algeria ... through the Algeria-Libyan border," the Foreign Ministry said in a statement published by APS news agency.

There was no indication as to the whereabouts of the Libyan leader.

Sofia is Gadhafi's second wife. Mohamamad is his eldest son and head of the Libyan Olympic Committte. Ayesha is a lawyer and former U.N. goodwill ambassador.