FALLUJAH, Iraq (Reuters) -- Iraqi police have placed the city of Fallujah in a total lockdown, banning traffic and pedestrians as they hunted for what they said was a group of Al-Qaeda militants carrying out a bombing campaign.
Schools were closed, shops told to be shuttered, and a curfew put in place from daybreak after explosions targeting police in the dusty city in the western desert province of Anbar, once the heartland of Sunni Islamist resistance to the U.S. invasion.
On April 7, a suicide bomber rammed his car into a police checkpoint, killing an officer and wounding nine other people at the south entrance to Fallujah, 50 kilometers west of Baghdad.
Two days before, two bombs which exploded in succession killed a police major and wounded another eight police officers in the centre of the city, shattering the city's relative calm.
"We are investigating targets. We have information that they conducted a series of explosions," police Colonel Mahmud al-Issawi told Reuters.
"We want to root out those elements to avoid future explosions and to ensure security and stability in the city."
The recent violence in Fallujah pales when compared to the average 10 bombs a day that still explode in Baghdad and the near daily shootings and bombings by a still active Sunni Arab insurgency in the provinces of Diyala and Nineveh.
But Anbar was once in the grip of Al-Qaeda and other insurgents, who battled U.S. forces in some of the bloodiest fighting after the 2003 invasion to topple Saddam Hussein, and authorities are loath to let them back in again.
Anbar's tribes eventually grew fed up with Al-Qaeda's brutal version of Islamic law and turned on it in 2006, forming the now U.S.-sponsored Awakening Councils, which helped drive the insurgency to ground and led to a steep drop in violence.
But police said they had intelligence suggesting the attackers planned an escalation.
"Outsiders who belong to Al-Qaeda have infiltrated from Diyala Province and Mosul. Their aim is to conduct terrorist acts inside the city," police Lieutenant Colonel Abd al-Aziz Saif said.
Saif said a special police force from Ramadi, Anbar's other large city, had come to Fallujah to reinforce its police.
The curfew imposed on the city while police conducted raids turned Fallujah into a ghost town.
A few shops were open. Pedestrians caught out in the open were told by police to go home. They fired shots into the air to clear those who resisted, witnesses said.