Medics appeared to remove one person on a stretcher but hid the person's identity behind multiple white umbrellas. It was unclear who was inside the ambulance or the helicopter. Upon landing at nearby Old Airport, the boys were taken via ambulance to Chiang Rai Prachanukroh Hospital, a hospital official told ABC News.
Of the 13-strong foreign dive team - mainly from Europe - three were escorting the children, while the remainder were positioned along the risky first kilometre stretch, where the boys will have to navigate through submerged passageways in some places no more than two feet wide.
Thai Prime Minister Prayuth Chan-ocha spoke Monday with the boys' family members, many of whom have been camped out at the cave rescue site since the team went missing.
Mr Narongsak said yesterday morning that the boys and their coach were physically and mentally strong enough to dive their way out of Tham Luang. The operation to get them out was supposed to resume only after new oxygen tanks could be placed along their route of escape, which is partially underwater.
More than 90 divers were involved in the rescue operation, which will continue today.
But as the divers reached their destination, the heavens opened, sending water cascading into the cave system.
Eight of boys and the coach remained inside the Tham Luang Nang Non cave complex as authorities paused the global effort until Monday to replenish air tanks along the treacherous exit route. Previously, the entire round trip through the cave network was thought to take about 11 hours.
"If Phra Pirun helps us, we might be able to do it very quickly", Narongsak said, again invoking the god of rain, who is widely revered in Thailand.
The same journey took six hours before pumps lowered the water level. They said rescuing the eight remaining boys and their soccer coach could take up to four days. But the Denver Fire Department captain said the rescue mission to save a youth soccer team in Thailand is "unbelievable".
The rescue operation commenced on Sunday afternoon, as monsoonal rain threatened to further flood the cave, making a rescue impossible, and possibly depriving the boys of oxygen.
"Primary path is basically a tiny, kid-size submarine using the liquid oxygen transfer tube of Falcon rocket as hull".
The boys, who are due to be taken to Chiang Rai hospital for further medical examination, are said to be in good health, with their condition described by officials as "not that bad".
It was 10am (4am United Kingdom time) when officials chose to begin what one expert said was "beyond a shadow of a doubt, the most complex rescue ever attempted in the caving world".
Authorities temporarily stopped rescue efforts on Monday to replenish air tanks along the cave's perilous exit course.
President Donald Trump said in a tweet on Sunday: "The U.S.is working very closely with the Government of Thailand to help get all of the children out of the cave and to safety". All four were rushed to a hospital 65km away in Chiang Rai. It had been feared that sustained heavy rain could raise water levels inside the cave, greatly hindering the rescue operation.
Doctors are monitoring them for any illnesses they may have picked up in the cave, and supervising efforts to build up their strength after they spent more than two weeks with little food and no natural light.
The rescue has captured the world's attention, and many have offered their ideas on how to get the team out.
"Hopefully useful", he said in one tweet.