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 the 12 trapped boys and their assistant coach.

The boys, aged between 11 and 16, went missing with the 25-year-old chaperone after soccer practice on June 23 as they set out to explore the Tham Luang cave complex in a forest park near the border with Myanmar.

Mae Sai police commander Komsan Sa-ardluan ordered the media to leave the cave area over a loudspeaker.

A large media contingent began packing up equipment including tripods and cameras, and moving down a muddy hill away from the mouth of the limestone cave.