Rebels' lightning advance into Tripoli, search for Gaddafi as two sons are captured

Thousands of heavily armed rebels drove straight into Green Square in Tripoli - renamed Martyr's Square - and encountered little or no resistance from Gaddafi's forces who either fled or surrendered their waepons.

Gaddafi meanwhile, relayed a number of short messages through state TV inciting the tribes to march onto Tripoli and to 'purify' the city.

Libya's rebels have also captured Muammar Gaddafi's son, Saif Al-Islam, the head of the rebel National Transitional Council told Al Jazeera television on Sunday.

"We have confirmed information that our guys have captured Saif Al-Islam," Mustapha Abd El Jalil said. "We have given instructions to treat him well so that he can face trial."

There were scenes of jubilation all over Libya throughout the night as thousands of people waved the revolution flag and tore pictures of Gaddafi.

There remain some small pockets of resistance, and a fierce battle is reported to be underway this morning around Gaddafi's compound in Bab Aziziya, in Tripoli.

Tanks are said to have opened fire on the rebels.