By Ned Parker, Isra' al-Rubei'i and Raheem Salman
BAGHDAD, May 16 (Reuters) - Thousands of civilians have fled Falluja since last week after the Iraqi military intensified shelling in a new bid to crush a five-month old Sunni uprising, killing scores of people in what residents describe as massive indiscriminate bombardment.
The mortars, artillery and what residents call "barrel bombs" rained for at least seven days on Falluja - a city that was the nemesis of U.S. troops a decade ago and is now the main battle ground in a war pitting the Shi'ite-led government against rebellious Sunni tribal chiefs and an al Qaeda offshoot.
More than 420,000 people have already escaped the two main cities of western Anbar province, Falluja and Ramadi, in fighting since the start of the year. Residents say the new pounding of Falluja's residential neighbourhoods appears aimed at driving out all remaining civilians in preparation for an all-out assault to defeat armed groups once and for all.
Prime Minister Nouri al-Maliki, who is trying to cobble together a coalition to keep himself in office for a third term after an April 30 parliamentary election, has vowed to destroy fighters who seized parts of Anbar province last year.
The mainly Sunni desert province borders on Syria, and many of the fighters belong to the Islamic State of Iraq and the Levant (ISIL), an al Qaeda offshoot waging war and holding territory on both sides of the frontier.
After several days of bombardment last week, the Iraqi military announced on Friday last week it was launching an assault on rural areas north, south and west of Falluja.
Since May 6 at least 55 people have been killed in Falluja, according to medical sources. The dead include civilians and fighters. More than 1,100 families - an estimated 6,000 people - fled the shelling, and more are still leaving, according to an Iraqi lawmaker, Liqa Wardi.
Falluja residents say the military is inflicting widespread damage, including using "barrel bombs" - powerful makeshift weapons made from high explosives, cement and metal parts packed into oil drums and dropped from helicopters.
Barrel bombs have gained notoriety in the region because of their use in neighbouring Syria by President Bashar al-Assad's forces to flatten buildings in rebel-held areas. The Iraqi government has denied using them and says it is taking care to avoid mass casualties.
"Despite the fact our brave forces and tribes are launching an extraordinary war and facing groups of suicidal killers, we are committed to targeting only the locations" of insurgents, said Maliki's spokesman Ali al-Moussawi on Monday. "There are strict orders to stay away from residential areas."
However, a mid-level security officer in Anbar province confirmed that barrel bombs had in fact been dropped in Falluja.
"It's the scorched-earth policy - the destruction of a whole area. The army is less experienced in house-to-house fighting, which the rebels have mastered. That's why they've resorted to this," said the officer who has been involved in planning to retake the city, speaking on condition of anonymity.
By Monday, the army's major effort to enter Falluja's southern areas had failed and ground operations had once more stalled. Residents say the "barrel bombs" finally stopped. Maliki and his generals still vow they will retake the city.
Civilians, who are escaping Falluja after holding out for months in what had become a ghostly place, blame both sides for their plight. They are convinced the Shi'ite-led government wants to obliterate their city, and also fault Sunni militants and tribal fighters for playing havoc with their lives.
"We are trapped in the middle," said Abu Hameed, who owned a private computer school before the fighting and fled to Iraq's northern Kurdistan region over the weekend. "We are living in the street in the middle of nowhere."
Abu Hameed described witnessing a fierce explosion last week he was sure was a barrel bomb. The blast just 300 meters from his home convinced him staying inside the city was a death wish.
"It was something really extraordinary. The dust and the smoke. It looked like a nuclear bomb," he said, adding his family raced out of the city within two hours of the explosion last Wednesday. "We ran like hell. "
Two other civilians interviewed by Reuters gave similar accounts of giant flames and mushrooming clouds that differed from the regular explosions they had witnessed caused by artillery, rockets and mortar fire.
Falluja has played a central role in the fate of Iraq's Sunni minority in the years since the U.S.-led invasion of 2003.
Shortly after the Americans arrived, the city, a short drive from Baghdad in the Euphrates valley, became an Al Qaeda bastion holding out against the Americans and Iraq's new Shi'ite elite. U.S. troops nearly razed the entire city twice in 2004 as they sought to defeat al Qaeda in the war's two deadliest battles.
Sunni tribes later became disenchanted with al Qaeda's strict rule and forged an alliance with the U.S. military to restore order and drive out insurgents. Falluja was rebuilt and many Sunnis looked to participate in Iraq's democratic politics.
But those gains have been wiped away in recent years as Sunnis became increasingly angry at perceived repression by Maliki's Shi'ite-led administration in Baghdad.
Sunni protesters clashed with government forces in December, and all-out warfare returned this January when ISIL, profiting from the breakdown in relations between Baghdad and Anbar's Sunnis, sent convoys of fighters to join fledgling rebellions in Falluja and Ramadi.
Sunni tribes that were once recruited by the Americans to fight against al Qaeda have tolerated ISIL fighters in their midst, sharing a common enemy in Baghdad.
"What I can see here in Falluja on the ground is a full cooperation and coordination between ISIL and the other fighting groups," one tribal fighter in Falluja said by phone last week. "All the groups, including ISIL are operating under the umbrella of the tribal leaders and clerics."
A Falluja man going by the name Mohammed who sent his family to Baghdad last week said ISIL fighters were now in control in the city, and more moderate tribal groups who had allied with them for tactical reasons were no longer able to negotiate.
"There is a group of gunmen who are extremists. They never accept any initiative, any solution. People are afraid of them because they kill. If they know that another armed group wants to have a dialogue, they punish them," he said.
"Neither the government nor the gunmen can control and end the crisis. People thought that it was a game to finish after elections, but now they discover it is not."
The Iraqi security forces say they killed "100 terrorists" in the first days of their assault. The commander of the Counter Terrorism Service's Golden Division, Falah Barwari, vowed on Facebook the "final hour was approaching" for Falluja.
The Iraqi troops took a bridge in a small area south of Falluja, near a dam which ISIL has occupied since April. But the insurgents repulsed a major assault on Nueimiya, an area on the city's southern outskirts, according to the mid-level security officer, Falluja residents and anti-government tribal fighters.
"The commanders are telling their leaders what they want to hear not what they should hear, only to keep their positions and further their greed," the mid-level officer said.
Qassim Fahdawi, the governor in Anbar until a year ago, who has been trying to mediate between Maliki and anti-government tribesmen, said no solution, political or military, is in sight.
"There is no serious progress," he said. "The prime minister is getting wrong information. He is misled."
At least 6,000 soldiers have died in the months of Anbar fighting, according to an Iraqi medical official, speaking on condition of anonymity. Diplomats say as many as 12,000 Iraqi soldiers have deserted.
Residents say shops stayed open and people were able to travel around the city until the shelling intensified last week. Abu Hameed said the fighters who manned checkpoints, dressed in black with their faces shrouded, were mostly friendly.
"I'd see them by the bank and by the city hall guarding these places," he said. "They are willing to help everyone in every way."
Nevertheless, security officials and some residents believe ISIL has rigged Falluja with bombs in preparation for an all-out army assault. Abu Hameed said he had seen holes dug one day on Falluja's main street and filled with cement the next.
A man who gave the name Farhan said he buried his brother on Tuesday last week after he was killed by a stray shell. The funeral was rushed in just 15 minutes so that the dozen mourners at the gravesite would not be spotted by government surveillance drones and targeted: "Even the dead are not safe," Farhan said.
On Sunday Farhan fled the city with his wife, two children and two suitcases, after a massive explosion of what he believed was a barrel bomb near their house. They drove to northern Iraq.
"We blame the Iraqi government. They started this. They are supposed to protect us," he said, "And second of all, we blame the armed groups, because we are caught in their fighting. We are the victims." (Additional reporting by Ahmed Rasheed; Editing by Peter Graff)