Rescuers have made final preparations to bring the 12 trapped children and their football coach out of the Tham Luang caves.
"Today is D-day. The boys are ready to face any challenges," rescue chief Narongsak Osottanakorn told reporters who were cleared from the cave entrance at mid-morning on Sunday.
"We are at peak readiness."
Scores of divers were seen entering the cave after dawn on Sunday, and shortly afterwards there were orders for "unnecessary personnel" to clear the area to "help victims".
No other information was given, and all media were ordered to retreat 2km from the cave, protesting all the way.
The preparations indicated that officials have abandoned all extraction plans except for helping the boys to swim and dive the approximately 5km from their refuge inside the cave to the outside world.
World experts had weighed in on the problem for days.
Technology guru Elon Musk, who is consulting on possible rescue methods, tweeted that he was considering "a tiny, kid-size submarine" for a rescue.
He added, "Continue to be amazed by the bravery, resilience & tenacity of kids & diving team in Thailand. Human character at its best."
