|Wednesday's rocket bombardment was the first attack on Misurata's main town in several weeks [Reuters]
Forces loyal to Muammar Gaddafi have fired rockets into rebel-held Misurata in the first artillery attack targeting the centre of the city in several weeks.
Although no one was reported injured, the attack prompted concern among residents, who had believed the siege on their city was broken after rebels drove out loyalist forces in mid-May.
"Everyone is worried. We don't know where to go anymore. Only when I die will I be safe," said Mohammed Mabrouk, who lives near one of two houses hit by the rockets. Two more landed in open areas.
Fierce fighting has been largely contained in Misurata's far western and eastern edges, where the rebel army is sustaining heavier casualties by the day from the better equipped and better trained government forces.
Two people were killed in a rocket attack south of the city, while there have been regular attacks in recent weeks near an oil refinery in Misurata port, Al Jazeera's Tony Birtley reported.
A child was killed and two others were wounded on Monday when a rocket exploded in a house near the port in the east.
|Al Jazeera's Tony Birtley investigates Gaddafi's legacy in the rebel-held city of Misurata
Rebels have been trying to advance west toward the town of Zlitan, where Gaddafi's soldiers are imposing a tight siege.
Libyan television said on Wednesday that "dozens" of people were killed in Zlitan after NATO naval ships shelled the town.
The report could not be independently verified because foreign reporters have been prevented from entering Zlitan.
If confirmed, the incident could further complicate the mission of the NATO-led military alliance, whose credibility has been questioned after it admitted on Sunday killing civilians in a Tripoli air strike.
A rebel spokesman called Mohammed told the Reuters news agency from Zlitan that NATO had been hitting loyalist military targets in the town on an almost daily basis.
He said Gaddafi's soldiers used their artillery positions in Zlitan to fire artillery shells toward Misurata.
"We hear the sound of artillery fire every night," he said. Four rebel fighters were killed and 60 others were wounded in fighting with loyalist forces on Tuesday in Dafniya, which lies between Zlitan and Misurata. Eleven rebel fighters were killed there a day earlier.
Rebels have made slow progress since NATO countries joined their fight to overthrow Gaddafi in March but are now trying to edge towards Tripoli from Misurata, east of the capital, and from the western mountains region to its southwest.
The going is especially difficult in Misurata.
"Gaddafi's forces have moved forward about a kilometre," Mohammed Grigda said at the field hospital in Dafniya just outside Misurata.
It was impossible to verify the information but a Reuters reporter in Dafniya saw that rebel mortar positions had edged back slightly.
In the western mountains, where the rebels made significant gains in recent weeks, NATO launched four air strikes on Tuesday against loyalist forces outside the town of Nalut near the border with Tunisia, a rebel spokesman there said.
Gaddafi allies denounce the bombing campaign as a foreign attempt to force a change of government and seize the North African state's oil. NATO states defend the operation as a UN-mandated mission to protect Libyan civilians.
NATO admitted on Sunday its strike destroyed a house in Tripoli. Libyan officials said nine civilians died. The Libyan government said on Monday that 19 people were killed in another air strike, raising more questions about the military mission.
Libyan officials say NATO forces have killed more than 700 civilians, but have not presented evidence of such large numbers of civilian deaths and NATO denies them.
In a further blow to Libya's leaders, the United States on Tuesday blacklisted nine companies owned or controlled by Gaddafi's government.
The sanctions prohibit US transactions with the companies, including the Arab Turkish Bank, North Africa International Bank and North Africa Commercial Bank.
US parliamentarians on Wednesday will consider two bills authorising limited military action in Libya.
Republicans and Democrats alike have expressed support for the intervention but have been angered by US President Barack Obama's refusal to seek congressional authorisation.
Some politicians on both sides have threatened to target funding for the war.