Libya: Gaddafi forces pound western city of Zawiya
Libyan leader Colonel Muammar Gaddafi's forces have intensified their campaign to wrest the western city of Zawiya from rebel control.
A fierce battle has raged all day, with government tanks pounding the main square, witnesses say.
Col Gaddafi also launched a diplomatic offensive, dispatching senior officials to Egypt and Europe.
The government has offered a reward for the capture of rebel leader Mustafa Abdel Jalil, the ex-justice minister.
The amount was 500,000 Libyan dinars ($400,000; £250,000).
Tanks and snipers
The outcome of the revolt that began in mid-February to end Col Gaddafi's 41 years in power appears to be hanging in the balance, say correspondents.
The BBC's Wyre Davies in Tripoli says the army seems to be hammering home its advantage over poorly equipped and badly organised rebel forces.
Zawiya, 50km (30 miles) from the capital Tripoli, has been battered over four days by government artillery, tanks and snipers.
One insurgent told Reuters news agency that government forces captured the main square on Wednesday evening, but it was later reported that the rebels had seized it back.
"We can see the tanks. The tanks are everywhere," said a fighter named Ibrahim. "There are many dead people and they can't even bury them."
A doctor in the city told the news agency that at least 40 people had been killed in the day's fighting.
One resident told the BBC that buildings had collapsed and people were trying to flee.
State TV reported that government forces were in full control of Zawiya, and showed pictures of what it said were residents staging a pro-Gaddafi demonstration.
A Libyan army captain said: "Security is at about 95%. There are some rats that could be lying in some alleys and inside some flats. We are capturing them one group after the other."
With journalists denied access to frontline areas, the rival claims are difficult to verify.
On the eastern front around the Mediterranean oil port of Ras Lanuf, rebels retreated in the face of heavy government shelling and fresh air strikes.
Huge explosions destroyed oil tanks in Ras Lanuf on Wednesday afternoon, sending a tower of black smoke billowing into the sky.
There were further major blasts in the nearby town of Sidra and reports that an oil pipeline had been blown up; government and rebel forces blamed each other.
Col Gaddafi meanwhile sent high-ranking members of his inner circle overseas on the eve of a Brussels summit, at which Nato defence ministers will discuss Libya.
Maj Gen Abdel Rahman al-Zawi was dispatched to Cairo, reportedly to bring a message from the Libyan leader to the Arab League.
Tripoli also sent a government emissary to Brussels, according to Italian Foreign Minister Franco Frattini.
Mohammed Tahir Siyala, the Libyan undersecretary for co-operation, flew to Malta for talks with its prime minister, the Maltese government told the BBC.
Mr Siyala is believed to have been the same Libyan official who then flew to Lisbon for talks with Portuguese Foreign Minister Luis Amado.
As the international community continued to debate the possibility of introducing a no-fly zone in Libya to stop government planes bombing rebel-held towns, Col Gaddafi remained defiant.
He told Turkish TV that he had no intention of quitting and again accused the West of trying to break Libya apart in order to get at its vast oil reserves.