The official leading the rescue efforts to free 12 children and their football coach, trapped in an underground cave in Northern Thailand, says rescuers may attempt to take them out with divers. It's considerably dangerous, as none of the children know how to dive, and some can't even swim. But with heavy rains forecast, it may be their only option, as Tony Cheng reports.

Rescue workers continue to struggle around the clock to find an exit for the trapped children and their coach.  But the options are narrowing.  Inside the cave, pumps are still operating to clear as much water as possible. Pumping the passages dry appears unlikely, however, as the caves refill when the pumps are paused. Outside the caves, attempts to find an alternative entrance have also stalled. And ambitious plans to drill an exit hole at least six hundred meters into their sanctuary, are proving to be exactly that. The former governor of Chiang Rai, in charge of the rescue operation, says there are also concerns that oxygen levels are running low in the caves, not just for the boys, but for the divers too. That, he says, may force them to take them out the way they came, despite the risks.

NARONGSAK OSOTTANAKORN RESCUE OPERATION CHIEF "Now and in the next two or three days, the conditions of the water level, weather and the boys' health are perfect. We have to make a clear decision on what we can do."

The one ray of light on Saturday, was the first messages from the boys themselves. Handwritten notes, on scraps of notepad, carried back by the navy seals. Titan, eleven, says he wants fried chicken when he gets home. Bew, fourteen, promises to help in his Mum and Dad's store every day. They all tell their parents not to worry that they're doing fine.

TONY CHENG THAM LUANG CAVE, NORTHERN THAILAND "The letter from the boys are not just good news for the patents who have been desperate for any news, but also for the hundreds of people currently trying to get them out. But these people, probably more than anyone else, know just how hard that task is going to be, Tony Cheng CGTN Tham Luang Cave Northern Thailand."