|The opposition remains defiant, saying it would not negotiate with Gaddafi to end the violence [Al Jazeera]
Forces loyal to longtime Libyan leader Muammar Gaddafi have shelled Misurata, pressing their siege of the embattled western city.
Four children were killed in the shelling on Tuesday, a resident named Mohammed Ahmed told the Reuters news agency. The children were killed while trying to flee their home, a rebel spokesman told Al Jazeera.
Gaddafi's regime has encircled Misurata for days, bringing in tanks and stationing snipers on rooftops, in an attempt to choke off one of the only cities in the west where a strong rebel presence remains. Shelling there killed at least 40 people on Monday, Ahmed said.
Misurata lies around 200km east of Tripoli, the capital, and is home to a major oil refinery.
Libyan government spokesman Ibrahim said Misurata, Libya's third-largest city, was "liberated three days ago" and that Gaddafi's forces were hunting "terrorist elements".
But a spokesman for opposition fighters in the city told the AFP news agency that the opposition remained in control despite an onslaught by Gaddafi loyalists, who he said opened fire with tanks and set snipers on roofs to gun down people in the streets.
"Casualties fell in their dozens," after snipers and a tank "fired on demonstrators", the spokesman said.
The opposition spokesman said Gaddafi's troops "have taken up position along the main road where they have deployed three tanks, as well as positioning snipers on rooftops".
Meanwhile, a US F-15 jet crashed in Libya late on Monday, reportedly due to a technical fault during a raid against anti-aircraft defences.
The US Africa command said on Tuesday that both its crew ejected safely. A command spokeswoman told AFP news agency that the crash was not a result of hostile action and an investigation to determine the cause
of the malfunction was underway.
Following the rescue there were reports that a number of local Libyans were shot and injured during the operation.
There was also fierce fighting further east in Ajdabiya. Opposition fighters were seen retreating in the face of an attack by government forces.
Al Jazeera's Tony Birtley, reporting from an area close to Ajdabiya, said there had been clashes outside the city.
"There's been heavy fighting and heavy shelling going on ... the rebels told me there have been heavy casualties and there are a number of corpses between here and the town [of Ajdabiya] that they have been unable to reach."
He said the road between the eastern city of Benghazi and Ajdabiya was littered with the "burned-out wreckage of what was Gaddafi's armour and tanks," destroyed in air raids by coalition forces.
Government troops retreated 100km from Benghazi, the opposition stronghold, after fierce strafing by coalition aircraft destroyed much of their armour, the AFP news agency reported.
Deaths in Zintan
Meanwhile, around 106km south of Tripoli, Libyan pro-democracy fighters forced government troops to withdraw from the outskirts of Zintan, breaking a siege of the town.
After enduring heavy shelling the day before, rebels on Tuesday pushed pro-Gaddafi troops out of the eastern outskirts of the city, a Swiss journalist, Gaetan Vannay, told Al Jazeera.
Gaddafi's forces withdrew around 10km east, to a village that is still controlled by Gaddafi, he said.
During their push, rebels managed to capture four regime tanks, Vannay said. The international military coalition that is enforcing a no-fly zone over Libya did not aid the rebels by launching air strikes against Gaddafi's forces.
A resident of Zintan told Reuters news agency that at least 10 people were killed in the bombardment by Gaddafi's forces.
"Gaddafi's forces bombarded Zintan this morning and killed 10 to 15 people," Abdulrahman said.
"After the bombardment they retreated from the eastern area of Zintan. But they have not withdrawn from the northern area. There is still a huge number of soldiers there, backed with 50 to 60 tanks and several vehicles."
Coalition warplanes hit targets across Tripoli for a third night on Monday and anti-aircraft fire lit up the sky. Two large explosions could be heard about 10 minutes apart shortly after 9pm, said Al Jazeera's Anita McNaught, reporting from the capital.
She said two naval installations just outside the city, one of them thought to be the Abu Sitr Naval Base, had reportedly been hit in the strikes.
"We could see an area of the port on fire, substantially on fire, two big blazes. We saw fire engines racing along the coastal road," she said.
"This evening seems to have been about targeting seaborne military assets of Gaddafi's army, but also we are given to understand [there was] an attack on the airport at Sirte."
As fighting raged in Misurata, international coalition forces reportedly struck radar installations at two air defence bases belonging to Gaddafi's forces in Benghazi in eastern Libya.