Libyan strongman Muammar Gaddafi's forces pressed rebels in the west on Wednesday and threatened their eastern bastion of Benghazi, as UN chief Ban Ki-moon called for an immediate ceasefire.


With clashes raging on several fronts and casualties rising, US Secretary of State Hillary Clinton said she hoped the UN Security Council will vote on new measures against Libya as early as Thursday that might include a no-fly zone.


Elsewhere in the troubled region, Bahraini police killed at least three protesters and wounded dozens Wednesday when they cleared a protest camp in the capital's Pearl Square, opposition sources said.


The interior ministry said two policemen also died in the assault on pro-democracy demonstrators at the symbolic heart of the Shiite-led uprising against the Sunni monarchy.


In the month-long revolt in Libya, Gaddafi loyalists killed two rebel fighters and two civilians in an assault on the country's third largest city of Misrata, a rebel spokesman reached by telephone said.


An independent witness in Zintan, the first western town to go over to the opposition, said "things were starting" there, as Gaddafi's son Seif al-Islam predicted everything would be over in 48 hours.


And witnesses in Ajdabiya, the gateway to Benghazi, said fighting was still going on there although government sources said it had fallen on Tuesday.


As talks resumed in the divided UN Security Council on a bid to secure a no-fly zone, Ban spokesman Martin Nesirky said the secretary general "is gravely concerned about the increasing military escalation by government forces, which include indications of an assault on the city of Benghazi.


"A campaign to bombard such an urban centre would massively place civilian lives at risk. The secretary general is urging all parties in this conflict to accept an immediate ceasefire and to abide by Security Council resolution 1970."


The resolution, passed on February 26, called for an end to Gaddafi's onslaught against opponents and imposed sanctions against his regime.


In Cairo, meanwhile, Clinton said "we want to do what we can to protect innocent Libyans against the marauders let loose by the Gaddafi regime."


"And yes, time is fast upon us. There is an urgency to it," she said in an interview with CBS television while visiting Libya's eastern neighbour Egypt.


Clinton stopped short of explicitly backing a no-fly zone, which has so far failed to gain enough international support to be imposed, saying only it was one of a number of options under consideration.


But she said the Arab League's endorsement of action against one of its own members, up to and including a no-fly zone, had had a major impact on the views of the major powers on the Security Council.


"I think that there was a sea change in opinion when the Arab League issued its statement on Saturday," she said.


Asked about opposition from veto-wielding permanent members China and Russia, Clinton said: "I think they are willing to talk about what's at stake here."


The United States has also been very cautious, while Germany favours putting new bite into the sanctions passed by the Council on February 26.


Britain, France and Arab nations are seeking to overcome resistance to a no-fly zone.


"What we want to do is move as fast as possible and we will be stressing the urgency of the need for action this morning," British Ambassador Mark Lyall Grant said in New York.


The two-part draft resolution calls for a no-fly zone and toughened sanctions against the Gaddafi regime, according to diplomats at the United Nations, which says the conflict has cost more than 1,000 lives.


In the turmoil, four New York Times journalists have gone missing in Libya, the paper said on Wednesday, as Britain's Guardian newspaper said one of its journalists has been freed from detention and safely left the country.


Libyan state television said on Tuesday that the army would soon move against Benghazi, and hundreds of people were streaming over the Egyptian border after fleeing Ajdabiya, Benghazi and other cities, an AFP correspondent said.


Gaddafi's son Seif al-Islam also said rebels would have safe passage out of the country.


"We don't want to kill, we don't want revenge, but you, traitors, mercenaries, you have committed crimes against the Libyan people: leave, go in peace to Egypt," he told Euronews.


Ironically, witnesses and coastguards said Libyan soldiers near the Tunisian border fired heavy weapons on rebels trying to flee by boat with their families.


Gaddafi's forces had attacked Ajdabiya, 160 kilometres south of Benghazi, on Tuesday, inflicting heavy casualties on outgunned rebel fighters.


It "is totally controlled and is being cleansed of armed gangs," state television said after a day of heavy fighting.


But a doctor told AFP by telephone from the town's hospital that fighting was still going on Wednesday in and around in Ajdabiya, which also guards the road to Tobruk and the Egyptian border in the rebel-held east.


"We received four bodies today, all rebel fighters," Abdelkarim Mohammed said, adding that 22 dead, mainly civilians killed by artillery or air strikes, were brought in on Tuesday.


In Bahrain, hundreds of riot police backed by tanks and helicopters moved into Pearl Square shortly after dawn Wednesday, a day after King Hamad declared a three-month state of emergency in a bid to quell the protests.


The king was boosted by the arrival in the strategic island state of troops from Saudi Arabia and the United Arab Emirates in line with a pact between the Arab monarchies of the Gulf.


US Secretary of State Hillary Clinton told CBS television that Gulf Arab states are on the "wrong track" in sending troops into Bahrain.


The protesters are demanding democratic reform from the Sunni dynasty that has ruled the archipelago - home of the US Fifth Fleet - for more than 200 years.


Opposition Al-Wefaq movement chief Sheikh Ali Salman said the regime was acting like Gaddafi and using "extreme brutality" against ordinary people, as Shiite anger grew across the region.


In Yemen, another regional hot spot, dozens of people were hurt when police fired live rounds and tear gas at anti-government demonstrators in the western port city of Al-Hudaydah, witnesses said.


And security forces in Damascus arrested more than two dozen demonstrators in a second day of rare protests that are banned under Syria's emergency laws.