Police are searching for an angler who went missing at a lake in Hokkaido, suspecting he may have been attacked by a bear after a human head was found in the area Monday, they said.

According to the police, a boat dropped off Toshihiro Nishikawa, 54, to fish unaccompanied at a spot on Lake Shumarinai in Horokanai early Sunday. An employee of the boat operator later saw a bear nearby with waders dangling from its mouth and attempted to call Nishikawa by phone, but could not reach him.

The information prompted the town office to launch a bear hunt operation and a member of the group killed one Monday afternoon, according to a town official.

A human head was also discovered during the operation. The police said they are investigating whether it is that of Nishikawa, a resident of Okoppe, also in Hokkaido.

The lake, located in northern Hokkaido, draws anglers trying to catch Sakhalin taimen, a rarely caught fish in Japan, as well as trout and Japanese smelt.