TRIPOLI: The US, Britain and France pounded Libya with Tomahawk missiles and air strikes into the early hours of Sunday, sparking fury from Moamer Qadhafi who declared the Mediterranean to be a “battlefield.”

In the biggest Western intervention in the Arab world since the 2003 US-led invasion of Iraq, American warships and a British submarine fired at least 110 Tomahawk cruise missiles into Libya on Saturday, the US military said.

Admiral William Gortney told reporters at the Pentagon the cruise missiles “struck more than 20 integrated air defence systems and other air defence facilities ashore.”

The action came two days after a UN Security Council resolution with Arab backing authorised military action to prevent Qadhafi forces from crushing an uprising against his 41-year autocratic rule.

An AFP correspondent said bombs were dropped early Sunday near Bab al-Aziziyah, Qadhafi’s Tripoli headquarters, prompting barrages of anti-aircraft fire from Libyan forces that lasted about 40 minutes.

State television had earlier said hundreds of people had gathered to serve as human shields at Bab al-Aziziyah and at the capital's international airport.

A Libyan official told AFP at least 48 people had died and 150 were hurt -- mainly women and children -- in the assaults, which began with a strike at 1645 GMT Saturday by a French warplane on a vehicle the French military said belonged to pro- Qadhafi forces.

Libyan state media said Western warplanes had on Saturday night bombed civilian targets in Tripoli, causing casualties while an army spokesman said strikes also hit fuel tanks feeding the rebel-held city of Misrata, east of Tripoli.

Qadhafi, in a brief audio message broadcast on state television, fiercely denounced the attacks as a “barbaric, unjustified Crusaders' aggression.”

He vowed retaliatory strikes on military and civilian targets in the Mediterranean, which he said had been turned into a “real battlefield.”

“Now the arms depots have been opened and all the Libyan people are being armed,” to fight against Western forces, the veteran leader warned.

Libya's foreign ministry said that following the attacks, it regarded as invalid the UN resolution ordering a ceasefire by its forces and demanded an urgent meeting of the Security Council.

The attacks on Libya “threaten international peace and security,” the ministry said.

“Libya demands an urgent meeting of the UN Security Council after the French-American-British aggression against Libya, an independent state member of the United Nations,” it said.

On Thursday, the Security Council passed Resolution 1973, which authorised the use of “all necessary means” to protect civilians and enforce a ceasefire and no-fly zone against Qadhafi forces.

The following day, Libya declared a ceasefire in its battle to crush an armed revolt against Qadhafi regime which began on February 15 and said it had grounded its warplanes.

As a result of the Western attacks, however, “the effect of resolution 1973 imposing a no-fly zone are over,” the ministry statement said.

State television, quoting a security official, said Libya had also decided to suspend cooperation with Europe in the fight against illegal immigration due to the attacks.

Boats carrying thousands of undocumented migrants, mainly Tunisians, have landed on the Italian island of Lampedusa in recent weeks putting a heavy strain on Italy's immigration infrastructure.

US President Barack Obama, on a visit to Brazil, said he had given the green light for the operation.

“Today, I authorised the armed forces of the United States to begin a limited military action in Libya,” Obama said, but stressed operation “Odyssey Dawn” would not send US troops to Libya.

The first Tomahawk missile struck at 1900 GMT on Saturday after air strikes carried out earlier by French warplanes, said Admiral Gortney, director of the US joint staff.

“It's a first phase of a multi-phase operation” to enforce the UN resolution and prevent the Libyan regime from using force “against its own people,” he said.

One British submarine joined with other US ships and subs in the missile attacks, he said.

Russia expressed regret over the attacks and said Resolution 1973 was “adopted in haste,” while the African Union, which opposed military action, on Sunday called for an “immediate stop” to all attacks.

China expressed regret over the air strikes, saying it opposed the use of force in international relations.

Japan, however, said it backed the multinational action, urging Qadhafi to make a “prudent decision”.

British Prime Minister David Cameron said he held Qadhafi responsible for the situation in his country.

“Tonight, British forces are in action over Libya. They are part of an international coalition that has come together to enforce the will of the United Nations and to protect the Libyan people,” Cameron said in London late Saturday.

“We have all seen the appalling brutality that Colonel Qadhafi has meted out against his own people and far from introducing the ceasefire he spoke about he has actually stepped up the attacks and the brutality.”

In the rebel camp, celebratory gunfire and honking of car horns broke out in Al-Marj, 100 kilometres (60 miles) from Benghazi, to welcome the start of military operations against Qadhafi, correspondents said.

Thousands earlier Saturday fled Benghazi as Qadhafi loyalists pounded the eastern city, the rebels’ stronghold, with shells and tank fire after two early morning air strikes.

UN chief Ban Ki-moon said he was troubled by a telephone call from Libyan Prime Minister Baghdadi Mahmudi 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 authorise 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.