Libya's provisional government forces have pushed their way to the gates of the oasis town of Bani Walid, one of the last remaining strongholds of ousted leader Moammar Gadhafi.

Anti-Gadhafi reinforcements poured into the area just outside the town Sunday. NATO warplanes flew overhead after also providing air support the day before. Smoke billowing from the town and a charred vehicle on the outskirts signaled Saturday's intense fighting.

NATO said its warplanes hit a multiple rocket launcher, a tank and two armed vehicles near Bani Walid on Saturday. NATO also hit targets near the pro-Gadhafi strongholds of Sirte and Sabha.

The National Transitional Council said anti-Gadhafi forces moved on Bani Walid Friday after Gadhafi loyalists fired a barrage of rockets at NTC positions.

Those fighters encountered stiff resistance from Gadhafi loyalists on Saturday, but authority forces expressed confidence they are close to victory despite the continued fighting.

There also are reports that NTC fighters are gathering outside other strongholds of pro-Gadhafi forces, including Mr. Gadhafi's home city of Sirte.

Mr. Gadhafi's whereabouts are unknown. Late Saturday, Guinea Bissau's prime minister said his country would welcome the ousted Libyan leader should he seek exile in that west African country. Guinea Bissau had strong ties to Mr. Gadhafi's government when he was in power.

Libya's provisional authorities had given three main Gadhafi-held towns until Saturday to surrender.

NTC leader Mustafa Abdel Jalil arrived in Tripoli Saturday for the first time since the Council's forces took over the capital in August. The NTC plans to move its headquarters from the eastern city of Benghazi to Tripoli as soon as the security situation allows.

On Friday, Interpol issued an arrest warrant for Mr. Gadhafi, his son Seif al-Islam and Libya's former intelligence chief, Abdullah al-Senussi.