Forces loyal to Libyan leader Muammar Gaddafi have launched new air raids on the oil city of Ras Lanuf and are closing in on the western town of Az Zawiyah.
Fresh reports of rockets landing on Ras Lanuf came on Wednesday, leading to a growing concern for the city's gas facilities, which if bombed, could spell disaster for people living in the area.
Jacky Rowland, Al Jazeera's correspondent in Ras Lanuf, said fighter jets were circling overhead and the rebels were firing back.
"What we are hearing is intense and repeated attacks by Gaddafi's airplanes on the rebels," she said.
"The air force is concentrating on the big junctions at the entrance to the town. The fact that it’s such consistent black smoke could well means there is oil underneath it. It is continuing to burn.
"The opposition fighters are extremely panicked."
Khaled Kwafi, a member of the opposition forces based on the outskirts of Ras Lanuf, told Al Jazeera that people were killed and injured in the attack.
"An hour ago we saw warplanes in the sky. We heard very huge explosions and lots of smoke. Our people tried to go there but they were stopped," he said.
"We heard there are people killed and injured there."

Rebels under pressure

Aside from attacks in Ras Lanuf forces loyal to Gaddafi launched a bombardment near rebel positions around the east Libyan oil terminal of Es Sider on Wednesday, blowing up storage tanks at the facility.
Rebels retaliated by firing back with rockets as a fireball exploded from one of the oil tanks and the sky above the terminal filled with black smoke.
Gaddafi's forces are also reported to have surrounded the rebel-held town of Az Zawiyah, close to the capital Tripoli.
Tanks of forces closed in on the rebel-held main square of on Wednesday and their snipers shot at anything that moved, rebel and resident sources said.
They said bodies were lying unrecovered in the ruins of many buildings destroyed in air raids earlier in the week and there was no one in the streets of the centre.
"We can see the tanks. The tanks are everywhere," a rebel fighter told Reuters by phone from inside the city.
The Libyan government claims it has taken back the coastal town of Bin Jawad after heavy shelling there.
Gaddafi himself remains as defiant as ever, saying the Libyan people will take up arms if western powers get involved in events in Libya.
On Wednesday, three of his private planes left Tripoli. At least one of them, carrying a high-ranking official for talks with the head of the Arab League, landed in the Egyptian capital, Cairo.

Gaddafi blames foreigners

Earlier, in his second televised speech in as many days, Gaddafi once again alleged involvement of foreigners in the rebellion against his more than 41-year-old rule.
In an address on state TV early on Wednesday he warned of a plot to colonise Libya. As proof, he said his security forces had captured several foreigners during a raid on Monday.
"Yesterday, the mosque that the security forces regained power over, they had in this mosque, they had weapons and alcohol as well. Some of them come from Afghanistan, some of them come from Egypt, some of them come from Algeria, just to misguide our children," Gaddafi said.
His address followed an offer by the rebels, granting him a safe exit.
"If he leaves Libya immediately, during 72 hours, and stops the bombardment, we as Libyans will step back from pursuing him for crimes," Mustafa Abdel Jalil, head of the opposition National Council, told Al Jazeera on Tuesday.
"Conditions are that firstly he stops all combat in the fields, secondly that his departure is within 72 hours; thirdly we may waive our right of domestic prosecution ... for the crimes of oppression, persecution, starvation and massacres," Jalil said.
The offer came amid reports that Gaddafi had sent feelers to the opposition movement, expressing willingness to negotiate his exit.
Unconfirmed reports indicated that Gaddafi was willing to step down in return for having war crimes charges against him dropped and a guaranteed safe exit for him and his family.
He also reportedly wanted guarantees from the UN that he will be allowed to keep his money.
Libyan state television has, however, denied the reports. An official from the Libyan foreign ministry described the reports as "absolute nonsense".
Hoda Abdel-Hamid, Al Jazeera's correspondent in the eastern city of Benghazi, said she was hearing conflicting accounts of what happened.
"The head of the opposition National Council says there were indirect talks with people from Tripoli, who were given the green light from the regime," she said. "But the spokesman for the National Council denies any of that."