May 27 (Bloomberg) -- Japanese troops based in southern Iraq, where they are distributing aid and helping to rebuild hospitals and other infrastructure, heard explosions near their base, Chief Cabinet Secretary Hiroyuki Hosoda said.

No explosions were reported within the perimeter of the base, Hosoda said. Japan has about 600 soldiers in the area.

Mortars have been fired near the camp in two earlier incidents, with no injuries reported. Prime Minister Junichiro Koizumi won lawmakers' approval for the troop dispatch after he pledged not to send them to a conflict area.

Dutch troops, who are responsible for security in the area, have also been attacked. One Dutch soldier was killed in a grenade attack earlier this month.

To contact the reporter on this story: Tim Kelly in Tokyo at tikelly@bloomberg.net

Last Updated: May 26, 2004 22:47 EDT