Libyan rebel forces have controlled Tripoli except Bab Al-Aziziyah and are clearing up the remnants of Libyan leader Muammar Gaddafi's forces, National Transitional Council's senior official Abdullah Almayhop said.
Rebel soldiers were seen waving opposition flag in the downtown Green Square, where most of the government departments are located.
Almayhop said that Gaddafi's eldest son Mohammed has surrendered to the rebels.
Mustafa Abdul Jalil, the head of Libya's National Transitional Council (NTC), said in an TV interview earlier Sunday night that Saif al-Islam, Gaddafi's second son, had been captured and was under custody in a safe place.
The International Criminal Court (ICC) prosecutor's office confirmed that Gaddafi's son Saif al-Islam has been detained. The ICC issued arrest warrants on June 27 for Gaddafi, his son Saif al- Islam and intelligence chief Abdullah al-Senussi, charged with crimes against humanity.
Jalil said that Gaddafi's guards in Tripoli had surrendered to the opposition troops.
Meanwhile, Gaddafi said in an Audio speech on Sunday that all the tribes and people should march to Tripoli to "purify" the city, according to the State TV.
"The west will not protect you," he said, "Tripoli will be destroyed."
He urged all the imams of mosques to guide people to protect the capital.
The spokesman for Libyan leader Muammar Gaddafi's government Moussa Ibrahim said on Sunday that 1,300 people had been killed in the fighting in Tripoli since noon Sunday.
He said at a press conference in Tripoli that 5,000 people were wounded in the battle and the NATO should be held responsible for the bloodshed.
He said that the country needs Gaddafi and people should be encouraged to fight for him.
Opposition convoy entered the western district of Tripoli on early Sunday evening with almost no sign of resistance, Al-Jazeera TV channel reported.
Residents of the city began to stream into streets to welcome the opposition troops, despite Gaddafi's call to urge people to take up arms to guard his rule.
Thousands of people flock into the streets in Benghazi, ready to celebrate for the collapse of Gaddafi's rule.