Ground Self-Defense Force troops in Iraq will remain inside their camp near Samawah for the time being following last week's roadside explosion near a GSDF convoy, Defense Agency chief Yoshinori Ono said Tuesday.

Ono said the bomb, which slightly damaged one vehicle in the convoy, was a remote-controlled device placed about 2 meters from the side of the road.

He said he shared this information with other ministers during informal discussions following a Cabinet meeting Tuesday morning.

"We hope, if possible, to find out information such as whether (the explosion) was targeted at the Self-Defense Forces and who is responsible for it," Ono said.

Early Wednesday morning, another huge explosion was heard in Samawah near the Muthana provincial council building shortly before 1 a.m. No other details were immediately available.