Tokyo, May 16 : Police are searching for an angler who went missing at a lake in Japan's northernmost prefecture of Hokkaido, suspecting he may have been attacked by a bear after a human head was found in the area, local media reported on Tuesday. According to the police, 54-year-old Toshihiro Nishikawa went missing while fishing unaccompanied on Sunday at Lake Shumarinai in the town of Horokanai, Xinhua news quoted Kyodo News as saying in its report. A bear was spotted later in the day nearby with fishing waders dangling from its mouth, the Kyodo News report added. Local officials said the information prompted the town office to launch a bear hunt operation and the search team killed one on Monday afternoon, the report said. A human head was also discovered during the operation in the area, and the police are investigating whether it is that of Nishikawa, Kyodo News said. Hokkaido police said bear sightings are on the rise this year, and they received 339 reports up to May 11, 40 more than in the same period last year, when bears were spotted a record 2,240 times, according to a report by public broadcaster NHK. /IANS