Six Vietnamese sailors may have jumped off a Taiwanese fisheries ship in the Tsuruga Strait off southern Hokkaido, the Japan Coast Guard said late Sunday, prompting ships and aircraft to scour the area.

A body was found floating about 5 km off the village of Kazamaura, Aomori Prefecture, on Sunday afternoon, according to the Japan Coast Guard. Although the body appears to be that of a man, it remains unclear whether it is one of the six men suspected of jumping from the 2,944-ton Taiwan-registered ship on Saturday evening.

A crew member saw six Vietnamese colleagues aged from 18 to 23 jump into the strait between Aomori and Hokkaido without life vests at around 8:50 p.m. Saturday, the Japan Coast Guard said.

No abnormalities or trouble on the ship have so far been reported.