FALLUJAH - Iraq is preparing a “major attack” to retake militant-held Fallujah, a senior official said Sunday, spelling a new assault for the city, west of Baghdad, where US forces repeatedly battled insurgents.Washington said it would help Baghdad in its fight against Al-Qaeda-linked militants but that there would be no return of US troops. The takeover of Fallujah and parts of Anbar provincial capital Ramadi, farther west, is the first time militants have exercised such open control in major cities since the height of the bloody insurgency that followed the US-led invasion of 2003. “Iraqi forces are preparing for a major attack in Fallujah,” a senior Iraqi official told AFP. Special forces have already conducted operations inside the city, the official said. The regular army has paused on the edge of the city to allow residents time to leave, after which it will launch “the attack to crush the terrorists”.Fallujah is in the hands of fighters of the Al-Qaeda-linked Islamic State of Iraq and the Levant, a senior security official said on Saturday. Secretary of State John Kerry said on Sunday that the United States would provide assistance to Iraqi forces in their battle against the militants but that it was “their fight”.Kerry said Washington was “very, very concerned” about the resurgence of ISIL but said it was not contemplating any return of US ground troops, after their withdrawal in December 2011. “We are not obviously contemplating returning, we are not contemplating putting boots on the ground, this is their fight,” Kerry told reporters in Jerusalem. “But we’re going to help them in their fight... We are going to do everything that is possible to help them.”ISIL militants seized control of the village of Bubali near Ramadi after heavy fighting on Sunday, a witness said. And AFP journalists reported sporadic clashes both inside Ramadi and on the outskirts of Fallujah.Iraqi ground forces commander Staff General Ali Ghaidan Majeed told AFP that security forces killed 11 militants from countries including Afghanistan and various Arab states on the highway from Baghdad to Fallujah.Majeed admitted that “we do not know what is happening in Fallujah,” but said the city should “wait for what is coming” - a reference to the impending assault.On Friday and Saturday, more than 160 people were killed in the worst violence to hit Anbar province in years.Both Ramadi and Fallujah were insurgent strongholds in the years after 2003, and Fallujah was the target of two major assaults in which US forces saw some of their heaviest fighting since the Vietnam War.American troops eventually wrested back control of Anbar from militants, with the support of Arab tribesmen of the Sahwa militia, who joined forces with the US from late 2006.Meanwhile, car and roadside bombs exploded in commercial areas of Baghdad on Sunday killing at least 19 people, police and medical sources said. The deadliest attack took place in northern Baghdad’s district of Shaab where two car bombs went off killing at least nine people and wounding 25.In a separate incident, gunmen set up a fake check point on the main road between Baghdad and Kirkuk, killing six drivers, late on Saturday near Udhaim, 90 km north of Baghdad, police said.