Saipan police on Tuesday called off the search for two Japanese tourists missing since June 29, when they are believed to have set out to sea in an inflatable raft.
Natsuki Yamada, 33, and her sister Chinatsu, 26, were last seen on a closed-circuit camera in their hotel late that day. Police said they were dressed for water sports.
Their rental car was found parked at Wing Beach, located near their hotel, with the car keys and some cash wrapped in a towel on the beach.
Also found on the beach were paddles and a raft pump. A deflated raft that was apparently used by the sisters was recovered from the sea last Wednesday.
Police say there was no sign of foul play and they believe the sisters went for a night swim in an area known for strong currents.
They arrived in the U.S. territory in the Northern Mariana Islands on June 28.
They were reported missing after their rental car was not returned on time and they did not board their scheduled flight back to Japan on June 30.