Four Iraqis, including a policeman, were killed and two US soldiers wounded in violent incidents at a marketplace in Baghdad's western suburb of Abu Ghuraib. Following Friday midday prayer, Iraqis gathered to protest what they said was the destruction of their market stalls by US forces. "The police tried to contain the protest, the protesters opened fire and a policeman was killed," said police Major Mussa Lazem. US troops later opened fire, according to medic Abbas Jassim who said three civilians were killed and at least 10 wounded. Earlier the same day, two US soldiers were wounded in a grenade attack at the market, according to US army Lieutenant Joseph Harrisson. It was not clear whether the two incidents were linked. The New York Times reported that U.S. commanders believe the ousted president is actively plotting some of the attacks against the US forces. Starting around midnight Thursday, U.S. soldiers, Iraqi police and civil defense forces moved into Uja, a small village about 16 kilometers southeast of Tikrit where Saddam was born. Soldiers stretched concertina wire around the perimeter of the village and established checkpoints. Residents over the age of 18 will be required to have registration cards to move in and out of the village, U.S. officers said, The AP reported. "This is an effort to protect the majority of the population, the people who want to get on with their lives," said Lt. Col. Steve Russell, commander of the 1st Battalion, 22nd Infantry Regiment of the 4th Infantry Division. Russell said he did not know whether Saddam was directing parts of the attacks, but the village is the family home of many former Baathist regime members. "There are ties leading to this village, to the funding and planning of attacks against U.S. soldiers," Russell said. In Fallujah, west of Baghdad, a strong explosion on Friday shook the center of this city, and thick black smoke billowed from the mayor's office, witnesses said. The blast was heard about 1:35 p.m., and Iraqi police blocked off the roads leading there. Meanwhile, a roadside bomb exploded near a U.S. foot patrol on the outskirts of the northern city of Mosul and unidentified gunmen sprayed the city hall with automatic fire, officers said Friday. Nobody was injured in these incidents. **PHOTO CAPTION*** Iraqis protest in front of a picture of former Iraqi leader Saddam Hussein after American troops clashed with rioters in Baghdad's suburb of Abu Ghraib, Friday, Oct 31, 2003. (AP Photo/Karim Kadim)