Baghdad  - A civilian was killed Friday and three others were wounded in the northern Iraqi city of Kirkuk, amid reports of a blast in Fallujah, some 70 kilometres west of Baghdad.

The Voices of Iraq (VOI) news agency said that one person was killed when an explosive device targeted people gathered in the Romaniya area in Kirkuk. Three others were injured in the explosion.

Sources told VOI that the injured were moved to hospital after the blast, while security forces started an investigation.

In western Fallujah, sources told VOI that an explosion occurred in an area where almost all the city's governmental offices and the police station are located.

Heavy black smoke was seen rising from the blast scene.

The reason for the blast was not immediately known, but an investigation was under way.

The blast is the second in the area after a suicide bomber detonated his vehicle in Dobat district injuring two people on May 18.

In other news, US soldiers said Friday they had arrested suspected weapons smugglers in Iraq.

The army said the men, believed to be Shiite Muslims, were bringing anti-tank munitions, missiles and other weapons from Iran into the province of Diyala.

One of the four is responsible for carrying out many attacks on US soldiers and members of the Iraqi security forces in the Husseiniya region, north of Baghdad, the army said.

The US Army accuses the Shiite leadership in Tehran of arming radical Iraqi militias and of training fighters from the Mahdi Army led by radical cleric Moqtada al-Sadr. (dpa)