Sustained automatic gunfire and a series of explosions rang out in Tripoli overnight as rebels launched efforts to permanantly free the Libyan capital from Muammar Gaddafi's grasp, according to reports from witnesses and rebels.
Blasts and gunfire rocked the city after sunset on Saturday, and witnesses reported street protests and fighting in the eastern neighbourhoods of Souq al-Jomaa and Tajoura. Beginning at around 9pm local time, residents also took to the streets in the Fashloum, Fournaj, Sabah, Ghoud al-Shayal, Hanshir and Dahra areas, many of them emerging from mosques and chanting "God is great".
Expatriate Libyans speaking to family members in the capital said their relatives described men going out to protest, some with weapons, while children and women were asked to stay home. Meanwhile, NATO aircraft reportedly carried out bombing raids after nightfall.
Government spokesman Moussa Ibrahim said rebels had tried to attack Tripoli but had been "dealt with".
Ibrahim appeared on state television in the early morning hours in Tripoli's central Green Square, riding in a car and surrounded by tens of supporters. Gaddafi himself never appeared, though he released an audio message congratulating citizens for repelling an attack by "rats".
"Sure, there were some armed militants who escaped into some neighbourhoods and there were some scuffles," Ibrahim said. "But we dealt with it within a half hour and it is now calm."
Ibrahim said that pro-regime volunteers had repelled insurgents' attacks in several neighbourhoods. He dismissed mounting speculation that the regime was on the brink, but more gunfire was heard after he spoke on television.
Gun battles and the explosion of apparent mortar rounds could be heard clearly at the hotel where foreign correspondents stay in the capital. Their movements are tightly restricted by the regime.
In a live audio broadcast aired on state television early on Sunday morning, Gaddafi congratulated his supporters and accused French President Nicolas Sarkozy of trying to steal the country's oil. He said that the rebels were "bent on the destruction of the Libyan people".
Gaddafi urged his supporters to "march by the millions" and end a months-long rebellion, which he termed a "masquerade".
A senior official in the rebel National Transitional Council (NTC) said on Sunday that operations in Tripoli were co-ordinated between opponents of Gaddafi in the city and the rebels in the east.
"The zero hour has started. The rebels in Tripoli have risen up," said Abdel Hafiz Ghoga, vice-chairman of the NTC, in the eastern city of Benghazi.
"There is co-ordination with the rebels in Tripoli. This was a pre-set plan. They've been preparing for a while. There's co-ordination with the rebels approaching from the east, west and south," he said.
Ghoga said NATO warplanes were launching raids to distract Gaddafi's forces.
"The next hours are crucial. Many of their (pro-Gaddafi) brigades and their commanders have fled." He added.
'Operation Mermaid Dawn'
Colonel Fadlallah Haroun, a military commander in Benghazi, said the battles marked the beginning of Operation Mermaid Dawn. Tripoli's nickname in Libya is "Bride of the Sea," or mermaid.
Haroun told the AP news agency that weapons were assembled and sent by tugboats to Tripoli on Friday night.
"The fighters in Tripoli are rising up in two places at the moment - some are in the Tajoura neighbourhood and the other is near the Matiga airport," he told Al-Jazeera.
Tajoura has been known since the beginning of the uprising in February as one of the Tripoli neighborhoods most openly opposed to Gaddafi's rule. The Matiga airport is located in the city, while the international airport is located around 30km south.
A rebel representative for Tripoli on the NTC told the AP that rebels were surrounding almost every neighbourhood in the capital, and there was especially heavy fighting in Fashloum, Tajoura and Souq al-Jomaa.
In Benghazi, thousands of Libyans celebrated in the main city square, shooting fireworks and guns into the air, and waving rebel flags.