Heavy explosions rocked the Libyan capital at dawn on Thursday, as opposition fighters wrested two key villages in the western mountains from forces loyal to embattled leader Muammar Gaddafi.
Six explosions were heard in the center of Tripoli, near the fortified Bab al-Aziziya compound of Gaddafi, with smoke could be seen rising in the area at dawn.
The compound has been the target of a number of NATO air strikes after the western alliance imposed a no-fly zone in the country in March.
On the other hand, opposition fighters snatch two villages in the western mountains, as they continued to push deeper into government-held territory south of Tripoli.
The two villages in the mountain area about 150km south-west of Tripoli had been used for months by pro-Gaddafi forces to shell opposition-held towns.
"The revolutionaries now control Zawiyat al-Babour and al-Awiniyah after pro-Gaddafi forces retreated this morning from the two villages," Abdulrahman, an opposition spokesman in the nearby town of Zintan, told Reuters.
In Gharyan, a Gaddafi-held town that forms the gateway from Tripoli to the mountains, there was an undercurrent of tension as the frontline moves closer to the capital.
Meanwhile, a Russian envoy is due to hold talks with the Libyan government in Tripoli as part of attempts to mediate in the conflict.
The envoy, Mikhail Margelov, last week met opposition representatives in Benghazi.
Gaddafi's government has said it would accept a ceasefire and political talks, but only if the Libyan leader is allowed to keep his position - something NATO says is unacceptable.