Protesters threw stones at a convoy of Japanese troop vehicles Sunday in Iraq, breaking a mirror on one of the vehicles, officials of the Ground Self-Defense Force said.

The incident took place in Rumaythah near the GSDF's camp in Samawah as about 40 demonstrators, some apparently armed, surrounded a facility during a ceremony to mark completion of repairs by GSDF personnel, they said.

The demonstrators were members of a Shiite group headed by cleric Muqtada al-Sadr, local police said.