By Michael Georgy and Caren Bohan
TRIPOLI/WASHINGTON (Reuters) - President Barack Obama said Friday the international community was "tightening the noose" on Muammar Gaddafi, but Libyan rebels said their three-week-old insurrection could fail without a no-fly zone.
European Union leaders meeting in Brussels Friday said they would consider all options to force leader Gaddafi to step down but stopped short of endorsing air strikes, a no-fly zone or other military-backed means.
Obama, accused by critics of reacting too slowly, said he believed international sanctions, an arms embargo and other measures already in place were having an impact.
"Across the board we are slowly tightening the noose on Gaddafi. He is more and more isolated internationally," Obama said. "I have not taken any options off the table."
But Gaddafi's forces, with air supremacy and a big advantage in tanks, appeared to be maintaining the momentum on the ground.
The sound of explosions and small arms fire came from the oil port town of Ras Lanuf Friday as government troops landed from the sea, backed by tanks and air power.
Rebels had advanced until the town of Bin Jawad about 60 km (38 miles) west of Ras Lanuf a week ago, but have been driven back across the strip of desert and scrub. Though out-gunned, they have kept up stiff resistance.
"Ras Lanuf is a ghost town. There are skirmishes between rebels and Gaddafi forces going back and forth," said rebel captain Mustafa al-Agoury, adding that rebels were positioned on the east and Gaddafi's forces on the west of the town.
Neither side had full control, although Libyan state television said the town was cleared of "armed gangs" opposed to Gaddafi and a spokesman for the rebel movement, Hamid al-Hasi, told Al Arabiya that Ras Lanuf was back in rebel hands.
"TIME FOR ACTION"
Gaddafi's warplanes are carrying out air strikes seemingly unhindered by insurgent anti-aircraft guns mounted on the back of pick-up trucks.
Many rebels were angry at international inaction.
"Where is the West? How are they helping? What are they doing," shouted one angry fighter.
Gaddafi's son Saif al-Islam told the rebels they faced a full-scale assault to crush their uprising which began after Hosni Mubarak was overthrown in neighboring Egypt a month ago.
"It's time for action. We are moving now," he told Reuters in an interview Thursday.
In Tripoli, Libyan security forces used tear gas and fired in the air to disperse worshippers near a mosque before they could even attempt any protest, a Libyan said, citing witnesses.
The revolt in Zawiyah, 50 km (30 miles) west of Tripoli and held by rebels for days against fierce attacks, appeared to have been definitively crushed.
Foreign journalists brought to the city center by government forces Friday saw buildings scorched and pockmarked by bullets, patches of fresh paint and loyalists chanting "I love Gaddafi."
The facade of a hotel on the square that had been the rebel command center was scorched and in ruins. Facades not covered by large cloths were pockmarked by bullets from days of battles around the open space the rebels called Martyrs' Square.
The only town now holding out in western Libya is Misrata, about 200 km (125 miles) east of Tripoli. It was calm Friday, but rebels said they were expecting an attack to come soon.
Libya's insurgent leader warned that any delay in imposing a no-fly zone could let Gaddafi regain control.
"We ask the international community to shoulder their responsibilities," Mustafa Abdel-Jalil, head of the rebels' National Libyan Council, told the BBC.
"The Libyans are being cleansed by Gaddafi's air force. We asked for a no-fly zone to be imposed from day one, we also want a sea embargo," he said.
Some 15,000 worshippers gathered outside the courthouse that has become the headquarters of the National Libyan Council in the rebel stronghold of Benghazi.
"Help us to become a democratic country," said one banner strung between lampposts and written in English and Arabic.
The 27 EU leaders meeting in Brussels sidestepped a British and French initiative for a U.N. Security Council resolution that would authorize a no-fly zone.
They also did not back French President Nicolas Sarkozy's call to follow his lead and recognize the National Libyan Council as the country's legitimate authority, or his call for "defensive" air strikes against Gaddafi's forces if they used chemical weapons or warplanes against civilians.
Libya Friday suspended diplomatic relations with France.
German Defense Minister Thomas de Maiziere said flatly that the situation in Libya was "not the basis for any kind of military intervention by NATO."
"The issue needs to be resolved in Libya and the region ... Military actions need to be thought out. We cannot get ourselves into something which we later are not convinced about and which cannot be pushed through," he told reporters in Brussels.
(Additional reporting by Maria Golovnina in Zawiyah, Mohammed Abbas in Brega, Tom Pfeiffer in Benghazi, Luke Baker, David Brunnstrom, Missy Ryan and Lucien Toyer, James Mackenzie and Justyna Pawlak in Brussels, Paul Eckert and Tabassum Zakaria in Washington, Stefano Ambrogi and Olesya Dmitracova in London, John Irish in Paris, Stephanie Nebehay in Geneva, Harry Papachristou in Athens; Writing by Jon Hemming and Sonya Hepinstall; editing by Philippa Fletcher)