The group entered the cave on June 23 and got trapped as floodwaters tore in.

Highlights Along with the coach, the kids also wrote heartfelt notes to parents

"I am fine but the weather is cold", wrote one kid

The boys are still inside the cave and are being given diving lessons

The 25-year-old coach of a youth football team trapped for two weeks in a Thai cave has offered his "apologies to the parents" of the boys in a scrawled note released by the Thai Navy on Saturday.

Thailand is holding its breath for the safe return of the group, with heavy rains forecast and fears mounting over the reduced oxygen and high level of water in the cave.

Ekkapol Chantawong was for nine days the only adult with the children -- aged 11 to 16 -- until they were discovered on a muddy ledge by rescue divers on Monday.

"To all the parents, all the kids are still fine. I promise to take the very best care of the kids," he said in a note given to a diver on Friday and published on the Thai Navy SEAL Facebook page on Saturday.

"Thank you for all the moral support and I apologise to the parents."

Other touching notes signed by members of the "Wild Boar" team were directed to their families, many of whom have kept an anxious vigil outside the cave for a fortnight.