Tokyo has been criticized by environmental groups for its weak presence and slow response in tackling an oil spill disaster caused by a Japanese freighter that ran aground off Mauritius in the Indian Ocean last month.

On Aug. 10, four days after oil started to leak from the Wakashio vessel, Japan dispatched a six-member relief team, but the government has maintained a distant attitude about the crisis compared with countries such as France and India, according to the groups and local residents in Mauritius.

"The Japanese government seems to be on the defensive, perhaps due to fears of damages claims," said Kanna Mitsuta, executive director of nongovernmental organization Friends of the Earth Japan, a member of Friends of the Earth International.