Two died in a double mortar attack late on Saturday on an American-run prison west of Baghdad which has come under resistance fire before. Further mortar assaults occurred on Sunday.
A US military statement said none of the inmates at the Abu Gharib prison, about 20km from the Iraqi capital, was killed in the mortar attack late on Saturday.
"Two 800th Military Police Brigades soldiers died and 13 were wounded when two mortars hit the Abu Gharib prison," the statement said.
Abu Gharib prison, which houses 500 prisoners, has been the scene of frequent attacks. The last fatal assault was on 16 August when five Iraqi detainees were killed and 67 wounded by mortars.
Aljazeera's correspondent from Baghdad, said mortars were usually fired at the jail at night from behind the cover of palm trees that dot the prison outskirts.
US Brigadier General Janis Karpinski told reporters on a tour of the prison facility last week that "four nights out of seven we get attacked with mortars, rocket or AK-47s".
Elsewhere, the US military headquarters in the northern Iraqi city of Mosul was targeted by mortars, said witnesses on Sunday. They were unable to specify if there were any casualties.
Two mortars were fired at about 7.45 pm (15:45 GMT) at the US headquarters near Mosul University, they said.
US infantry soldier guards an
Iraqi after a raid in Tikrit
US soldiers cordoned off the sector and closed a nearby bridge, an AFP correspondent said, adding that smoke could be seen rising from the US headquarters and helicopters were flying overhead.
Ten people near the city were injured later Sunday in a grenade attack by unidentified assailants against a shop selling pornographic video cassettes, witnesses said.
"At 10:20 pm (18:20 GMT), unidentified persons in a white van threw a grenade at a shop selling pornographic cassettes in Annabi Younis," a village near Mosul, around 400 km north of Baghdad, said one witness, Mohamed Abd Allah Muhammad, 37.
"Ten people were injured and the shop was badly damaged," he said, adding that the Iraqi police, backed by US troops, launched a search for the assailants.
Another witness, Abd Hussain Yahia, a 40-year-old taxi driver, said "similar types of shops have received written threats warning them not to sell such cassettes."
Residents in the town of al-Khaldiyah, north of Baghdad, said a US military vehicle was damaged when it hit a landmine on Sunday. The device was planted on the road linking Ramadi with Falluja. There was no word of any casualties.
In another incident a US soldier was killed in a bomb attack on a military vehicle on Saturday in the Iraqi town of Ramadi, west of Baghdad, the US army said on Sunday.
It said the blast went off at about 9.30pm (17:30 GMT) in Ramadi - regarded as a hotbed of support for ousted leader Saddam Hussein located 100km (70 miles) from the capital.