Tongan police launched a high-seas chase yesterday after a US man accused of murder escaped from custody and attempted to flee the Pacific nation on his yacht. Police said Dean Jay Fletcher escaped from Vava'u Police Station, in the country's north, in the early hours of yesterday. A police launch with 10 officers on board located the 54-year-old a few hours later about 10km offshore and they were trying to apprehend him "The escaped prisoner is refusing to stop and making threats to himself and police officers, which has not allowed for a safe boarding at this stage, Tonga police said.