TRIPOLI (Reuters) - Russia joined Western leaders on Friday in urging Libyan leader Muammar Gaddafi to step down and offered to mediate his departure, in an important boost to NATO powers seeking to end his 41-year rule.
It was a striking change in tone from Kremlin criticism of NATO air strikes in Libya, which are officially intended to protect civilians in a civil war but have effectively put the West on the side of rebels seeking Gaddafi's removal.
NATO said it was preparing to deploy attack helicopters over the Arab North African state for the first time to add to the pressure on Gaddafi's forces on the ground.
But his security forces demonstrated once again that they are far from a spent force, launching rocket attacks overnight on the rebel-held town of Zintan and fighting insurgents on the outskirts of the city of Misrata.
Russia's mediation offer was announced on the sidelines of the Group of Eight summit in Deauville, France, where Russian President Dmitry Medvedev discussed the situation with U.S. President Barack Obama.
Libya's official news agency has widely referenced Russia's criticism of Western air strikes on Libya as going beyond a U.N. Security Council mandate to protect civilians. Medvedev however emphasised that Gaddafi no longer has the right to lead Libya.
"The world community does not see him as the leader of Libya," Medvedev said, adding that he said he was sending an envoy to Libya to begin talks. He presented no plan to remove Gaddafi from power.
U.S. State Department spokesman Mark Toner said Russia's proposal was one of a variety of mediation efforts, adding that Gaddafi must be held accountable and should not expect special treatment.
"We want Gaddafi to step aside and for a peaceful democratic transition to take place," he said. "The U.N. obviously has appointed someone to lead that mediation as well. We believe that that also should be the focus."
In Tripoli, Deputy Foreign Minister Khaled Kaim told a news conference the government had not been officially informed of the Russian position. "Any decision taken about the political future of Libya belongs to the Libyans, no one else," he said.
A NATO-led coalition has been bombing Libya since March, under a U.N. mandate to protect civilians caught up in a battle with rebel forces intent on ending Gaddafi's rule.
But the rebels' advance towards Tripoli has been checked hundreds of km (miles) short of their goal, creating a quandary for Western powers who want a quick outcome in Libya but also to avoid getting embroiled in another Middle Eastern conflict.
Britain and France have tried to break the deadlock by agreeing to deploy attack helicopters over Libya. Prime Minister David Cameron said in Deauville the deployment of helicopters was part of a new phase in NATO operations in Libya.
"There are signs that the momentum against Gaddafi is really building. So it is right that we are ratcheting up the military, the economic and the political pressure," Cameron said.
Gaddafi has denied attacking civilians, saying that his forces were obliged to act against armed criminal gangs and al Qaeda militants. He says the NATO intervention is an act of colonial aggression aimed at grabbing Libya's bountiful oil.
There was scepticism that Gaddafi would agree to step aside, even with Russia now also calling for his departure. "Knowing his state of mind, I don't think he is going to step down," Arab League Secretary-General Amr Moussa said in Deauville.
Previous attempts at mediation, by the African Union, Turkey and the United Nations, have foundered on Gaddafi's refusal to leave and the rebels' refusal to accept anything less.
Rebel-held Misrata, Libya's third biggest city and scene of some of the fiercest battles in the conflict, was hit by a second day of heavy fighting on its western outskirts.
Doctors at Misrata's hospital said five rebels were killed and more than a dozen wounded in the fighting on Friday.
The World Health Organisation said the fighting in Misrata had been killing an estimated 12 people a day, an estimate that would mean a total of about 925 killed over the last 77 days.
Gaddafi's forces intensified their attacks too on Zintan, part of a chain of mountain settlements near Libya's border with Tunisia, where rebels have been holding off assaults for months.
A foreign doctor in Zintan, about 150 km southwest of Tripoli, said the town came under intense rocket fire overnight from pro-Gaddafi forces positioned to the east.
"There must have been about a hundred (strikes)... there were four or five rockets every half an hour or 15 minutes," Anja Wolz of Doctors Without Borders said by telephone.
In the rebel-held east Libyan city Benghazi, the rebel administration in Benghazi is trying to present itself as a credible government-in-waiting.
That effort was helped on Friday when Farhad Omar Bin Guidara, Libya's central bank governor until he left the country in February, said he was working with the rebel finance team.
(Reporting by Joseph Logan in Tripoli, Mohammed Abbas in Misrata, Souhail Karam in Rabat, Matt Robinson in Tataouine, Tunisia, David Brunnstrom in Brussels, Joseph Nasr in Berlin, Steve Holland, Keith Weir, Alexei Anishchuk and Nicolas Vinocur in Deauville, France and Barbara Lewis in Geneva; writing by Christian Lowe and Jan Harvey; editing by Maria Golovnina)