Antiwhaling activists protested Monday as the mother ship in Japan's whaling fleet left for the annual hunt in the Antarctic, the environmental group Greenpeace said.
The Nisshin Maru left the port of Innoshima near Hiroshima in the afternoon under tight security, Greenpeace said. The rest of the fleet is expected to leave from another port this month.
Officials refused to comment, citing concerns the departure might be disrupted.