Libyan rebels, backed forcefully by European leaders, rejected a cease-fire proposal by African mediators on Monday because it did not insist Muammar Gaddafi relinquish power.

Despite an earlier announcement that the Libyan leader had accepted the truce, his forces shelled a key rebel-held city and killed six people, a doctor said.

"Col. Gaddafi and his sons must leave immediately if he wants to save himself," said Mustafa Abdul-Jalil, head of the rebels' leadership council. "If not, the people are coming for him."

Even as the African Union delegation arrived in the eastern rebel stronghold of Benghazi, crowds of protesters gathered to demonstrate their opposition to any dealmaking while Gaddafi remains in power. They said they had little faith in the visiting African Union mediators, most of them allies of Gaddafi. Three of the five African leaders who came preaching democracy for Libya seized power in coups.

Abdul-Jalil, a former justice minister who split with Gaddafi and leads the Benghazi-based Transitional National Council, said the proposal "did not respond to the aspirations of the Libyan people" and only involved political reforms.

"The initiative that was presented today, its time has passed," said Abdul-Jalil. "We will not negotiate on the blood of our martyrs. We will die with them or be victorious."

Italian Foreign Minister Franco Frattini strongly backed the rebel demand for Gaddafi's immediate departure and said he doubted anyway that the Libyan leader would have abided by the cease-fire after he broke more than one pledge before to halt violence. The AU sought a suspension of three weeks of international airstrikes on Gaddafi's forces, that have prevented them from overpowering the vastly weaker rebel forces.

The secretary general of NATO, which took over control of the international air operation over Libya from the U.S., welcomed any efforts to resolve the conflict. He said it had become clear it would not be decided on the battlefield.

"There can be no solely military solution to the crisis in Libya," Anders Fogh Rasmussen said.
Gaddafi's forces, meanwhile, battered the rebel-held city of Misrata and its Mediterranean port with artillery fire, despite the African Union delegation's assurance that Gaddafi had accepted their cease-fire plan at a meeting late Sunday in Tripoli. A doctor who lives in the city said the shelling began overnight and continued intermittently throughout the day Monday.

He said six people, one of them a 3-year-old girl, were killed by missiles that slammed into residential areas. He spoke on condition of anonymity because he feared retaliation if he was discovered by Gaddafi's forces.

Weeks of fierce government bombardment of Misrata, the only major city in the western half of Libya that remains under partial rebel control, has terrorized its residents. Dozens have been killed and food and medical supplies are in short supply, according to residents, doctors and rights groups.

Wary of Gaddafi's earlier broken cease-fire pledges, European officials supported the rebels' refusal to negotiate until Gaddafi and his powerful sons and associates are gone.

"The sons and the family of Gaddafi cannot participate in the political future of Libya," Frattini said on France's Europe-1 radio. He said Gaddafi's departure would have to happen "in parallel" with any cease-fire.

He said he was lobbying allies to arm the rebels but that he was against expanding the international operation to include ground forces. The rebels have far less equipment, training and troops than Gaddafi's forces, and members of the international community have grown doubtful the opposition can overthrow Gaddafi even with air support.

Speaking in London later, Frattini said Gaddafi's past crimes make it extremely difficult to imagine the Libyan leader will respect a cease-fire.

NATO is operating under a U.N. resolution authorizing a no-fly zone and airstrikes to protect Libyan civilians.

More than 1,000 protesters in Benghazi waved the pre-Gaddafi flags that have come to symbolize the rebel movement and chanted slogans against Gaddafi, whose more than 40-year rule has been threatened by the uprising that began nearly two months ago.

"I was born in the same year Gaddafi took power and I've never seen anything good from him. He is the biggest lie in the history of Libya," said 42-year-old protester Jilal Tajouri. "All the people in Libya agree on this: Gaddafi and all his sons must leave Libya so we can have democracy."

An Algerian member of the AU delegation had said there was discussion in the meeting with Gaddafi of the demands for his exit, but he refused to divulge details.

South African President Jacob Zuma led the group, whose other key participants were the leaders of Mali, Mauritania, Republic of Congo and Uganda.

NATO airstrikes on Sunday hit Gaddafi tanks, helping the rebels push back government troops who had been advancing toward Benghazi on an east-west highway along the country's northern Mediterranean coast.

The airstrikes largely stopped heavy shelling by government forces of the eastern city of Ajdabiya — a critical gateway to Benghazi, the opposition's de facto capital and Libya's second largest city.

On Monday, rebels held positions at the western gates of the city, on the fringes of desert littered with bullet casings, scraps of metal and more than a dozen blackened or overturned vehicles, including tanks and pickup trucks outfitted with anti-aircraft guns.

The area was also scattered with twisted cooking pots, torn blankets and a shredded green helmet smeared with blood.

A rebel scout sent down the highway to the west said he encountered Gaddafi forces and was drawn into a brief gunbattle before falling back to Ajdabiya, but there were no major battles on that front Monday.