A car bomb has killed four people and wounded at least 38 in the northern Iraqi city of Mosul.

Police say the bomb exploded Saturday in a market in eastern Mosul.

Violence declined ini most of Iraq in recent months, but bombings continue in Baghdad and Mosul.

In a separate incident, a truck driver was mistakenly killed by a U.S. soldier who fired on the truck early Friday after its driver did not respond to warnings to stop as the vehicle approached a U.S. convoy.

A spokesman for the U.S. military expressed regret for the loss of life and called the incident a tragic event.

The shooting is under joint U.S. - Iraqi investigation.

Meanwhile, an American soldier was sentenced Saturday to three years in prison for accidentally killing a fellow soldier in January.

Sergeant Miguel Vegaquinones was also reduced to the rank of Private and dishonorably discharged from the Army.

U.S. troops withdrew from Iraqi cities at the end of June, transferring security responsibilities to Iraqi forces.

In political news, a group of Iraqi lawmakers loyal to Shi'ite cleric Moqtada al-Sadr staged a protest Saturday against a proposal allowing British troops to remain in the country. The lawmakers walked out of Parliament during the discussion of a deal to allow up to 100 British troops to stay in Iraq beyond a previously approved withdrawal date.

The Britons would be responsible for helping the Iraqi navy protect oil installations off its southern coast.

Some information for this report provided by AP, AFP and Reuters.