Libyan rebel fighters
Libyan rebel fighters ride through the town of Maia celebrating after advancing to the outskirts of Tripoli, August 21, 2011. Bob Strong

Hundreds of rebel fighters entered the centre of the Libyan capital, Tripoli, late on Sunday and their battle to overthrow the 42-year rule of Muammar Gaddafi looks set to end in their favour as reports of Gaddafi's sons being arrested emerged.

While previous reports suggested Tripoli, Gaddafi's stronghold, would provide the Rebels with their toughest battle yet, on Sunday, opposition flags could be seen on the main buildings all around the capital, and people were cheering "Go Gaddafi" in the streets.

The Gaddafi troops, it seems defected the regime, leaving the rebels free to reach Tripoli's central Green Square, the symbolic heart of the city, also known as the martyrs' square, in the early hours of Monday morning.

While confrontations between the Gaddafi forces and the rebel fighters are still on-going, and many deaths on both sides are reported, the NTC forces had first thought the advance into Tripoli would have taken them another few weeks.

Residents were also seen pouring into the streets to celebrate and greet the rebel fighters as they advanced through the suburbs towards the centre.

The prosecutor of the International Criminal Court said one of Gaddafi's sons, Saif al-Islam, who has been indicted along with his father on crimes against humanity charges had now been detained, information confirmed by the National Transitional Council, (NTC).

Responding to fears surrounding the detention conditions of the leader's son, the head of the rebel Transitional National Council, Mustafa Abd el-Jalil said that his fighters who had detained Saif al-Islam would "treat him well".

There were also reports that Gaddafi's eldest son, Mohammed, and the presidential guard had also been arrested but Gaddafi's Bab al-Aziziya compound is still under the control of the leader's forces, while Gaddafi's whereabouts are still unknown.

Despite a desperate call on people to take up arms against the rebels, inhabitants of Tripoli sided with the rebels, dismissing the call for fight.

Speaking on state television via audiolink, Gaddafi told the Libyan people: "There are criminals, they are coming to destroy Tripoli. They are coming to steal our oil.

"Now it [Tripoli] is in ruins. They are coming, they are destroying it. Come out of your houses and fight these betrayers. Hurry up, hurry up, families and tribes, go to Tripoli. Call the tribes to go to Tripoli."

Libyan information ministry spokesman Moussa Ibrahim also insisted that Gaddafi forces would stand and fight. He said: "We are still very strong. We have thousands and thousands of fighters who have nowhere to go but to fight.

"Nato has intensified its attacks on and around Tripoli, giving immediate and direct support for the rebels' forces to advance into a peaceful capital of this great nation and the death toll is beyond imagination."

Reports of the Libyan government's calling on a cease fire late on Sunday, however, proved that the Gaddafi regime is on its way out. It seems unlikely the leader's forces can take back control over the capital and with two sons reportedly arrested; Gaddafi will have to decide his next move.

In view of the rebels advances however reports that the NTC forces and the Gaddafi forces are distributing arms to whoever claim to be on their sides are worrying and cannot come as a good news for Libya and its future. With large numbers of the population now armed, it will become increasingly difficult for the NTC to assert control over the population once Gaddafi is ousted or surrenders.