FALLUJAH, Iraq, November 8 (IslamOnline.net & News Agencies) - Thousands of US Marine and Army forces, backed by hellish air strikes, ground fire and tanks, began Monday, November 8, their massive assault on the bastion Iraqi resistance of Fallujah after US-picked interim Prime Minister Iyad Allawi gave the go-ahead for an all-out assault.

The skies above Fallujah, west of Baghdad, burned red as artillery, war planes and tanks pounded the city at the start of the operation dubbed “Phantom Fury”, reported Agence France-Presse (AFP)

About 12,000 US and Iraqi forces were taking part in “Operation Phantom Fury,” the US military's codename for an offensive to retake the resistance stronghold of Fallujah, a defense official told AFP Monday.

The assault on the city by a combined force of some 10,000 US and 2,000 Iraqi troops face a force that at one point was estimated to exceed 3,000 fighters, the official said, speaking on condition of anonymity.

“There is no confusion, if you're on the street, you're a bad guy. Ninety percent of the civilian population has left,” said the official.

That would leave about 30,000 civilians still in the city, which at its peak had a population of between 250,000 and 350,000 people.

The official said resistance forces were concentrated in certain areas of the city.

The prelude to the assault was a crushing air and artillery bombardment of the city that rose to a crescendo by Monday evening, with US jets dropping bombs around the clock and big guns pounding the city every few minutes with high-explosive shells, reported The Associated Press (AP).

“The first punch came from just north of the city, where Marine Regimental Combat Team 1 -- more than 4,000 Marines and Army troops, along with Iraqi allies -- had been massed Sunday night.”

Heavy gunfire ripped through the outskirts earlier as US and Iraqi troops ventured into the resistance-held city, while US warplanes pounded the center in several hours of bitter fighting that left at least 38 Iraqi fighters dead.

Allawi gave the go-ahead for the massive onslaught. (AFP)

Giving the green light for the assault, Allawi said he had authorized the US-led military to wrest the Sunni Muslim bastion from resistance hands.

Allawi had paid a surprise visit to his troops outside Fallujah shortly before the bombardment.

The interim Prime Minister imposed an indefinite curfew from 6:00 pm (1500 GMT) on Fallujah, saying that it would be lifted on an area-by-area basis as it was brought under government control.

Black smoke plumed above the western fringe of Fallujah, where US and Iraqi forces had seized the main hospital and two bridges in their first major foray before dawn, which pre-empted a day of violent clashes.

To this end, artillery shells earlier blasted in sporadic bursts, said an AFP correspondent inside, while another reporter embedded with the marines on the northwestern edge said that armored vehicles drove through the outer streets firing at buildings.

The US marines and Iraqi special forces met minimal resistance when they took control of the hospital and two bridges. But that changed within hours as they were forced to fight for the territory, using helicopters, planes and tanks, a pool reporter told AFP.

A number of buildings, suspected of being used by what Allawi and US military call “insurgents”, were destroyed and several others set ablaze following five hours of clashes that still raged on.

Allawi said that 38 “insurgents” had been killed in the initial clashes and four foreign fighters detained, including two Moroccans.

Violence also raged in the northwest where at least four 2,000-pound (900-kilogram) bombs were dropped, the AFP reporter with the marines said.

Marines poured into a complex of several buildings, including two apartment blocks, a school, a mosque and a government building, in the northwest sector.

About 230 Iraqis were found still living in the complex, some milling about in their underwear. They would be evacuated from the city, the reporter said, noting that women and children were among the inhabitants.

Marines picked two men out from the crowd, bound their hands together and demanded that they reveal the whereabouts of the Mujahadeen fighters. The pair were unable to give any information, so were reportedly released.

Some 20,000 US and Iraqi troops are gathered around Fallujah, a city that has come to symbolize resistance against Allawi's US-backed government US-led troops.

Allawi told a news conference that he had called on Arab leaders to help negotiate with the “rebels”, but added, “we have reached the conclusion that we have to take the decision that saves the political process and stability of the country.”

One day after declared a state of emergency across most of Iraq, the US-backed premier announced that emergency measures were being imposed on Fallujah and its sister restive hub on Ramadi.

Thousands of US troops are attacking Fallujah. (AFP)

Clamping down on movement, US troops banned men aged from 15 to 50 from entering or leaving Fallujah, warning they could become a target.

Women and children will be allowed to leave the city but cannot return until “order is restored,” the US military said, according to an AFP photographer with the troops.

US commanders estimate that 2,000 to 2,500 fighters, some loyal to Iraq's most wanted man Abu Musab Al-Zarqawi, are inside the city and its surrounding areas, ready to fight.

The military believes that another 10,000 men could join in the battle.

The US military has conducted an intensifying campaign of aerial bombardments against the city, coupled with artillery fire in recent days as chances of a peaceful resolution faded.

Attempts to broker a peaceful solution between Baghdad and local leaders collapsed last month after Allawi threatened Fallujah with invasion if they did not surrender militants, such as Zarqawi.

City leaders insist that the Jordanian-born Zarqawi, wanted for a string of deadly attacks and beheading of hostages, does not reside in Fallujah.

Arab states appealed Monday for both sides to spare civilian lives in the brewing bloody showdown. A previous siege of the city by US marines in April left hundreds dead and ended in a stalemate.