Rebels will not pursue Libyan leader Muammar Gaddafi over crimes, they say he has committed, if he steps down from his post in the next 72 hours, the head of the rebel National Libyan Council has told Al Jazeera.
"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.
He said the deadline would not be extended beyond 72 hours.
"Based on our love for our country we have proposed to the [Gaddafi's] indirect negotiators that a solution can be reached," Jalil told Al Jazeera.
"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.
"We will have to wait and see what the regime's response is."
Libyan state television on Tuesday denied reports that the Libyan leader tried to strike a deal with opposition forces seeking his removal. An official from the Libyan foreign ministry described the reports as "absolute nonsense".
However, a spokesman for the opposition National Council in the eastern rebel stronghold of Benghazi confirmed that a representative had sought to negotiate Gaddafi's exit.
Gaddafi was reported to have sent a representative to Benghazi on Sunday night to discuss a conditional plan to step down, Al Jazeera learned. The offer was provided on the condition that Gaddafi would be able to keep his assets and avoid prosecution.
The Libyan leader is said to be 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 wants guarantees from the UN that he will be allowed to keep his money.
The US responded to the alleged proposal by rejecting any amnesty for Gaddafi.
"Any departure from Libya does not exempt Mr Gaddafi or his family from any responsibility and accountability for what has occurred," PJ Crowley, spokesman for the White House, said on Tuesday.
Hoda Abdel-Hamid, Al Jazeera's correspondent in 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."
Abdel Hafiz Ghoga said talks with Gaddafi were not taking place.
"Our demands are as clear as the revolution. We are not negotiating at all," he said.
"We have appealed to the United Nations to impose a no fly zone in Libya to protect our families and to prevent any aircraft attacks like the ones you are hearing about."
Our correspondent said there was no optimism in Benghazi following news of the proposed deal.
"There is no more euphoria of a revolution," she said.
"People are worried it will move towards civil war which will continue for months on end. There is a realisation that there is no institution in this country - that you have to avoid chaos.
"It's a matter of waiting and seeing. Military commanders are continuing on their mission to get military structure to the group of volunteers [fighters] who are very disorganised."
Security forces loyal to Gaddafi have strengthened their military position in the last few days, squeezing rebel-held towns in the west and checking the advance of rebel militias westwards towards the capital, Tripoli.
On Tuesday Gaddafi forces used tanks and aircraft to attack the town of Az Zawiyah, 50 km west of Tripoli, but rebels
say they still control the town centre.
Al Jazeera heard reports that Gaddafi snipers were on rooftops shooting randomly from the main square and that they were storming houses in some neighbourhoods and killing residents.
Fighting is also intensifying in Ras Lanuf - a key Libyan oil terminal in the centre of the country - amid reports of several air strikes on Tuesday.
As casualties rise there doctors tell Al Jazeera that they are running out of supplies to treat the wounded.
Gaddafi supporters are moving eastward in an effort to push the rebels back and recapture fallen towns, with reports emerging on Monday that they took control of the central Libyan town of Bin Jawad.
However, fighting continued there on Tuesday, with Gaddafi forces carrying out aerial bombardments on rebel fighters.
The rebel forces say they will be outgunned if the government continues to unleash its air attacks on them and are pleading for the international community to impose a no-fly zone to prevent this.
"We don't want a foreign military intervention, but we do want a no-fly zone," rebel fighter Ali Suleiman told AP news agency.
"We are all waiting for one,'' he said. The rebels can take on "the rockets and the tanks, but not Gaddafi's air force''.
Barack Obama, the US president, and David Cameron, the British prime minister, agreed on Tuesday that
the "common objective in Libya" must be an end to violence and the departure of Gaddafi from power.
"The president and the prime minister agreed to press forward with planning, including at NATO, on the full spectrum
of possible responses, including surveillance, humanitarian assistance, enforcement of the arms embargo, and a no-fly zone," the White House said in a statement after a phone call between the two men.
The UN Security Council also raised the possibility of imposing a no-fly zone.
"There were lots of issues that were discussed this morning, the no-fly zone was one of the issues," UN under secretary general Lynn Pascoe said after briefing the 15-nation Security Council on Tuesday.
Hundreds if not thousands of people have died since Libya's uprising began on February 14 in an effort to end Gaddafi's more than 41-year rule, although tight restrictions on media make it near impossible to get an accurate number.
The number of people who have fled the violence in Libya since last month has passed 215,000 according to the International Organisation for Migration, most of them are foreign workers.
Meanwhile, on Tuesday a senior Red Crescent official said forces loyal to Gaddafi were blocking migrant workers from crossing into Tunisia, and forcing many to return to work in Tripoli.
Ibrahim Osman said about 30,000 migrant workers were rounded up and held in Libyan immigration buildings near the Tunisian border last week.
He said Gaddafi soldiers "pulled back'' 30,000 Bangladeshis, Egyptians and sub-Saharan Africans from the Ras Ajdir border crossing and they appear to have been forcibly returned to service jobs in the capital.
The UN refugee agency also warned on Tuesday that there was a critical shortage of long-haul flights to evacuate foreign migrants who have fled Libya to their home countries in Asia and Africa.