Libyan rebels have captured a military base defending Tripoli, the stronghold of long-time leader Moammar Gadhafi, while fighting is reported inside the city.

News agency reporters say rebel fighters are taking weapons and ammunition from the base, 27 kilometers west of the capital.

Rebels forces are pushing toward Tripoli from the town of Zawiya, which they captured earlier.

The rebels say they also control three districts of the capital after fighting inside the city overnight into Sunday. Witnesses in Tripoli reported anti-Gadhafi demonstrations in those districts late Saturday.

The rebels claim they were able to land some fighters in Tripoli by sea from the port of Misrata, east of the capital.

Rebels advancing from Zawiya said earlier that forces loyal to Mr. Gadhafi were pounding their positions with rockets and anti-aircraft fire.

A government spokesman said Tripoli is well protected by thousands of professional soldiers and he called the rebels “armed gangs” whose success can only be attributed to NATO.

In a political victory for the rebels, the Tunisian news agency TAP announced Sunday that Tunisia's government has officially recognized the Transitional National Council as the legitimate representative of Libyans.

Mr. Gadhafi urged his supporters in an audio message carried on state television late Saturday to “march by the millions” and squash the uprising. He dismissed the rebellion as an ill-fated attempt by “traitors” and “rats.”

In a separate speech airing Sunday, the Libyan leader's son, Seif al-Islam, said the government will not “abandon the fight.”

U.S. President Barack Obama was briefed on the situation in Libya by a senior security adviser. A U.S. spokesman said the White House believes “Gadhafi's days are numbered.”

Mr. Gadhafi has seen the areas under his control shrink significantly in recent weeks as rebels advance on Tripoli from the west, east and south after six months of fighting to end his four-decade autocratic rule.

NATO warplanes have been supporting the rebels by bombing pro-Gadhafi forces under a U.N. Security Council resolution authorizing military action to protect Libyan civilians from government attacks.

Meanwhile, two more Gadhafi aides appear to have defected. Officials with Libya's opposition National Transitional Council say the Libyan leader's former number-two, Abdel-Salam Jalloud, is in Italy Sunday after joining their ranks a day earlier.

Tunisian officials also said Libyan Oil Minister Omran Abukraa has decided not to return to Libya after a recent mission to Italy.