Thai rescue: Trapped boys' coach may be left alone in cave

The coach of a youth football team trapped in a flooded cave in northern Thailand will be the last out, and could be on his own underground for a lengthy period as he awaits his rescue.

Ekaphol Chanthawong, 25, will be left alone in the Tham Luang cave if diving teams continue their system of saving four boys at a time - a possibility chief rescuer Narongsak Osottanakorn wouldn't rule out.

Mr Ossottanakorn says the four-at-a-time system has been functioning well up until this point.

"For safety, the best number is four," he said.

Mr Chanthawong and the team he coaches became trapped on June 23, when flash flooding submerged part of the tunnel system they were exploring in the Chaing Rai region.

Eight of the 13 trapped in the cave system have now been rescued, more than two weeks after they first entered.

There has been talk that Mr Chanthawong could face criminal charges for leading the boys into the cave so close to monsoon season, but the boys' parents say they don't want that.

An apology note Mr Chanthawong wrote them emerged a few days ago. In it, he promised to care for the kids to the best of his ability and thanked them for their support.

The parents responded by saying they are "not angry" at him, and in turn thanked him for his commitment to their children.