Two bombs have exploded about 20 minutes apart in eastern Baghdad, killing at least 11 Iraqis and wounding dozens, officials say.

The American military also said five US troops died in separate attacks.

The first blast occurred at 5pm on Thursday, when a car bomb detonated near a gas station, killing at least two people and wounding 13, police Major Falah al-Mohammedawi said.

The second went off 20 minutes later in a bustling outdoor market, killing nine people and wounding 57, said al-Mohammedawi.

US toll

The US military said the five American troops died on Wednesday in separate attacks.

A roadside bomb blast killed three US soldiers south of Baghdad, while a fourth soldier died from wounds suffered in a small-arms fire attack in the capital's southwest, the military said.

A US marine was fatally wounded during combat near the western city of Falluja.

The deaths were the first of US personnel reported since 28 January and took the total of US military deaths to 2247 since the Iraq war began in March 2003, according to an Associated Press count.

Human remains

Also on Thursday, a shepherd found the partially buried bodies of 16 men on the eastern outskirts of Baghdad, each of whom had been shot multiple times, bound and blindfolded, police said.

All the victims appeared be aged between 30-40 years, wore civilian clothes and had no identity documents.

Also on Thursday, a US helicopter fired a rocket at a house in the Shia district of Sadr City after being shot at, the US command said.

The rocket damaged several houses, killing a young woman, residents reported. Shia politicians condemned the incident as reckless and provocative.

The US military said the exchange of fire took place at about 1am as US troops were pursuing a "known terrorist associated with Ansar al-Sunnah", a Sunni armed group.

US soldiers also detained two unidentified people before the attack inside Sadr City, the power base of Shia cleric Muqtada al-Sadr.

Salam al-Maliki, Iraq's transport minister, condemned the US attack and demanded compensation for victims.

Other attacks

Attacks continued on Thursday with two roadside bomb blasts targeting an American patrol and damaging two Humvees in Tarmiyah, 50km north of Baghdad, police Lieutenant Ali al-Bayati said.

The US military said there were no American casualties.

Another roadside bomb blast killed three Iraqi Army soldiers in eastern Baghdad's Ghazaliyah neighbourhood, said army Major Moussa Abdul Karim.

Attackers fired three mortar rounds at the Oil Concentrating Complex, 45km west of Kirkuk, triggering a fire but causing no casualties, police Captain Farhad Talabani said.

US troops sealed off the site as firefighters struggled to extinguish the blaze.

PHOTO CAPTION

Iraqi fire fighters battle a blazing fire ignited after a car bomb exploded in a petrol station in Baghdad's al-Amin neighborhood. (AFP)