Queensland police announced on Saturday two Japanese teenagers died after drowning in a lake on a popular tourist island north of Brisbane.

Police said the bodies of the two 16-year-old boys were found in the waters of Lake McKenzie, a picturesque freshwater lake on Fraser Island, on Saturday morning after they were reported missing from a tour group just after 5 p.m. local time on Friday.

In Yokohama the same day, Kanagawa University High School announced that two students who were participating in an international exchange program in Australia disappeared on Friday and were found dead Saturday. The two are believed to be the same students found dead on Fraser Island.

Local police will prepare a report for the coroner.

Fraser Coast Mayor George Seymour told the Australian Broadcasting Corporation the drowning deaths were "highly unusual."

"It's really unimaginable how somebody, let alone two people, could drown there," he said. "It's a calm lake in the middle of an island ... whatever has happened is highly unusual."

Fraser Island is located roughly 350 km north of Brisbane. The World Heritage-listed location is the largest sand island in the world.