Western warplanes are continuing to bombard targets deep inside Libya - as Nato has agreed to take over enforcement of the no-fly zone over the country.
British Tornado GR4 aircraft took part in a co-ordinated missile strike against Colonel Muammar Gaddafi's forces.
"The Tornado aircraft launched a number of guided Brimstone missiles at Libyan armoured vehicles which were threatening the civilian population of Ajdabiyah," Defence Minister Liam Fox said in a statement.
The rebels have been battling pro-Gaddafi forces on the outskirts Ajdabiyah for days but have made little progress in retaking the area.
Sky's Sam Kiley, outside Ajdabiyah, said: "Gaddafi has three tanks, we believe, dug into a position behind me. He's also got two Stalin's Organs - those are the multiple rocket launchers, a very devastating weapon mounted on the back of big truck that can fire 30 or 40 rockets at one time.
"So clearly they are not too troubled by these airstrikes otherwise these weapons would have been hidden away under tarpaulins so that they're not vulnerable."
Other airstrikes destroyed government tanks on the outskirts of rebel-held Misratah, but tanks inside the city escaped the bombardment.
Residents and rebels said government snipers were also still active in the area.
"The situation is very serious," a doctor in the town said. More than 100 people are reported to have been killed and hundreds wounded over the past week.
Sky correspondent Lisa Holland, reporting from Tripoli under Libyan government supervision, said: "People (in Misratah) now are holed up in their homes, there is a growing concern about the situation.
"Officials here are denying that the water supplies have been cut off to Misratah. In fact, they are painting themselves as heroes going back in and sorting it all out.
"The government is saying there is no fighting going on. That is contrary to the sights and sounds we're hearing and the images posted on YouTube and so forth from inside Misratah."
Residents of the western city said around 6,000 workers and family members from Egypt and other African countries were stuck in the port, under the eye of two Libyan warships.
One man said: "They haven't attacked but if they do, the thousands of workers will be the first victims."
News of Nato agreeing to take over enforcement of the no-fly zone came after France said it had hit an air base in central Libya and a government plane after it landed at Misratah airport.
A Libyan official also said fuel storage tanks and a telecommunications tower in the capital, Tripoli, were among places hit by what state TV called "colonialist crusaders".