THAM LUANG CAVE, Thailand - Thai authorities on Sunday said they plan to evacuate an area around a cave in northern Thailand where a dozen boys and their soccer coach have been trapped so that a "rescue operation" can take place.The announcement came as dark monsoon rainclouds loomed over the mountainous north of the country early on Sunday, potentially heightening risks at the cave where rescuers were still waging a "war with water and time" to save 12 trapped boys and their assistant coach.The boys, aged between 11 and 16, went missing with the 25-year-old after soccer practice on June 23 after they set out to explore the Tham Luang cave complex in a forest park near by the border with Myanmar."Assessing the situation now, it is necessary to evacuate the area for the rescue operation," said Mae Sai police commander Komsan Sa-ardluan over a loudspeaker. "Those unrelated to the rescue operation, please evacuate the area immediately."