Moamer Gaddafi's forces on Wednesday held back efforts by rebels to advance into the eastern city of Ajdabiya, while explosions reportedly rocked the Libyan capital Tripoli earlier in the day, dpa reported.
According to Libyan news website Brnieq, rebels vowed they would reclaim Ajdabiya, just west of the opposition stronghold Benghazi, by nightfall.
The reported attacks on the opposition there came less than 24 hours after Libyan Prime Minister al-Baghdadi Ali al-Mahmoudi declared a ceasefire. Two previous ceasefires have not been kept.
The opposition rebels fighting Gaddafi's forces said that the last three nights of coalition airstrikes "have weakened Gaddafi's forces, but that they still pose a threat," according to Brnieq.
Early Wednesday, CNN reported that coalition airstrikes were launched overnight near the city of Misurata, east of Tripoli, where the opposition said deadly attacks by Gaddafi's forces took place in recent days.
In Tripoli, it was not clear where the reported explosions occurred, but there was no anti-aircraft fire, according to a CNN report. Coalition forces have bombarded Tripoli with cruise missiles in recent nights.
Phone lines to Tripoli and other Libyan cities were down on Wednesday.
Libyan leader Moamer Gaddafi held a defiant televised address late Tuesday, saying "we will not give up" and calling on other Muslim countries to "take part in the battle against the crusaders."
However, three journalists detained by forces loyal to Gaddafi, including two employees of Agence France-Presse news agency (AFP), were released late Tuesday.
The journalists had been captured Saturday while covering fighting between Gaddafi forces and rebels near Ajdabiya.
French-based media rights watchdog Reporters without Borders said four Al Jazeera journalists and several Libyan journalists were still being held by Gaddafi's forces.
Meanwhile, in an interview with broadcaster ABC, US Secretary of State Hillary Rodham Clinton said that the US would hand over control of operations in the next few days.
The US Deputy National Security Advisor Ben Rhodes told reporters that US President Barack Obama, his French counterpart Nicolas Sarkozy and British Prime Minister David Cameron had agreed that "NATO should play a key role in the command structure."
Clinton also told ABC that Gaddafi had been exploring options for a future abroad, according to US intelligence.
People from his entourage have been "putting out feelers" to their contacts around the world, possibly with a view to where he could go if he has to leave the country, she said.