Tripoli — French air raids and US Tomahawk missiles pounded targets in Libya on Saturday, in an international campaign to prevent Muammer Qadhafi from crushing a month-old uprising against his rule.
A US warship fired Tomahawk cruise missiles into Libya, targeting Qadhafi's air defence sites, a senior US military official said.
Two days after a UN Security Council resolution authorised military action, French planes carried out an initial four air strikes, destroying several armoured vehicles of Qadhafi's forces, the French military said.
Libyan media said Western warplanes bombed civilian targets in Tripoli, causing casualties, shortly after France's launch of the multinational air campaign against Kadhafi.
State television said hundreds of people had gathered at Bab al-Aziziyah, Qadhafi's Tripoli headquarters, and at the capital's international airport, ahead of the widely anticipated air strikes.
"Crowds are forming around the targets identified by France," the television reported, showing pictures of flag-waving people gathering to serve as human shields.
Last week, a highly placed French source referred to Bab al-Aziziya, a military air base in Sirte, east of the capital, and another in Sebha in the south as likely targets of a strike.
Britain also said its forces were in action on Saturday, as Russia's foreign ministry expressed regret over the armed intervention under UN Resolution 1973 "which was adopted in haste."
According to France's army chief, a first French air strike took place around 16:45 GMT against "a Libyan vehicle clearly identified as belonging to pro-Qadhafi forces."
Within the next hour, French Rafale and Mirage 2000 fighter jets conducted three other strikes, destroying armoured vehicles of the Libyan forces in the eastern region of Benghazi, the rebels' stronghold, the military said.
The operations are to continue through the night, the military said.
In the rebel camp, celebratory gunfire and honking of car horns broke out in Al-Marj, 100 km(60 miles) from Benghazi, to welcome the start of military operations against Qadhafi, correspondents said.
As thousands fled Benghazi amid an assault by Qadhafi loyalists earlier on Saturday, French President Nicolas Sarkozy told a summit of world leaders in Paris that his country's fighters were poised to attack.
But Sarkozy said Qadhafi could still avoid the worst if he complied with the Security Council resolution by implementing a ceasefire to allow the diplomatic door to reopen.
UN chief Ban Ki-moon, however, said he was troubled by a telephone call from the Libyan prime minister on Friday night.
"He told me that the Libyan government was fully abiding by the Security Council resolution and there will be an immediate ceasefire," said the secretary general.
"But at the same time and overnight they were attacking Benghazi. It is very troubling; whatever they say must be verified."
Since Friday, the Libyan government has insisted it was observing a self-declared ceasefire, shortly after the Security Council voted to authorize the use of force against Qadhafi's troops to spare civilians.
The regime said its armed forces were under attack west of Benghazi, including by rebel aircraft, and had responded in self-defence.
On Saturday, Foreign Minister Mussa Kussa said Tripoli had met all its obligations under the UN resolution and asked Ban to send observers to monitor the ceasefire.
But the rebels, who have been trying to overthrow the Libyan leader for more than a month, said government troops had continued to bombard cities, violating the ceasefire continuously.
British Prime Minister David Cameron held Qadhafi responsible for the continued violence and said that "the time for action" had come.
"Colonel Qadhafi has made this happen. He has lied to the international community, he has promised a ceasefire, he has broken that ceasefire. He continues to brutalise his own people," Cameron told British television.
"And so the time for action has come. It needs to be urgent. We have to enforce the will of the United Nations and we cannot allow the slaughter of civilians to continue."
Qadhafi has defied the threats against, telling Sarkozy and Cameron, main sponsors of the resolution authorising military action, that they would regret interfering in his country's affairs.
Earlier, a huge plume of smoke rose over Benghazi, Libya's second city, as thousands of people fled eastward after a series of air strikes and sustained shelling, said an AFP reporter in the metropolis of one million people.
Correspondents redeployed along with civilians to al-Marj reported that Qadhafi tanks had entered the Mediterranean city by mid-morning.
A warplane crashed in flames in a residential area of Benghazi, triggering celebratory gunfire from the rebels, but an insurgent commander later admitted it was one of theirs and had been shot down by Kadhafi's forces.
Ban attended what host France said would be a "decisive" summit in Paris with US Secretary of State Hillary Clinton as well as countries in the European Union, Arab League and African Union.
Late on Friday, the French presidency said France, Britain, the United States and Arab countries demanded "that a ceasefire must be put in place immediately, that is, that all attacks against civilians must come to an end."
It added that "Qadhafi must end his troops' advance on Benghazi and withdraw from Ajdabiya, Misrata and Zawiyah," referring to rebel-held towns attacked or captured by government forces in past days.
"That is not negotiable," it said, warning that if Qadhafi did not comply with Resolution 1973, he would face "consequences" from the international community and "the resolution will be imposed by military means."
Speaking in Brazil, where he was on a visit Saturday, US President Barack Obama said "the people of Libya must be protected and in the absence of an immediate end to the violence against civilians, our coalition is prepared to act."
Rebels in Misrata said earlier that the city east of Tripoli was calm on Saturday, a day after they beat back an onslaught by Qadhafi forces, destroying heavy armour but suffering 27 casualties.
But a witness said government tanks had shelled rebel-held Zintan, 120 km (75 miles) southwest of Tripoli.
In another Middle East hotspot, medics in Yemen on Saturday raised to 52 the death toll from a sniper attack on protesters in Sanaa the previous day, as thousands rallied despite a state of emergency.
The slaughter in Sanaa on Friday was the bloodiest day in weeks of unrest that have shaken the regime of President Ali Abdullah Saleh, a key US ally in its war against Al-Qaeda.
And security forces in Syria fired tear gas on Saturday at mourners burying two men killed in a protest in the southern city of Daraa the previous day, wounding several, rights activists said.
The official SANA news agency said a committee was being formed to investigate the "regrettable" events in Daraa.
In Bahrain, beleaguered King Hamad pledged to bring in reforms as Shia-led pro-democracy protesters against the Sunni monarchy said they would not give up despite being cleared by police from Pearl Square in central Manama.
