The second phase of a rescue operation has ended for the day, with more than half of the Thai soccer team rescued from the cave.
Four boys were rescued on Sunday and they were judged as healthy as they recovered in an area hospital.
Chiang Rai Gov.Narongsak Osatanakorn said Tuesday's rescue operation began at 10.08 a.m. and involves 19 divers.
Thai governor Narongsak Osottanakorn described the first rescue as "our masterpiece work" and claimed the four rescued boys were in "perfect" health - despite earlier reports that one was being "closely monitored". Monsoon flooding cut off their escape and prevented rescuers from finding them for nearly 10 days.
The boys first went missing on June 23 and were found on Monday, July 2 by two British divers huddled on a narrow rock shelf deep within the flooded cave system. Having completed this section, the boys are then handed over to separate, specialist rescue teams, who help assist them through the remainder of the cave, much of which they can wade through.
"Football's Coming Home. First Wild Boars Out", a headline on one online Thai paper said on Monday, referring to a song chanted by English soccer fans at the World Cup now underway in Russian Federation.
The names of the rescued boys were not released.
"Doctors have treated the boys, and now all of them are OK and cheerful and are talking normally", said Jesada Chokedamrongsuk, permanent secretary of the Thai Ministry of Public Health. Billionaire Elon Musk dispatched a team of engineers, and President Donald Trump said Sunday the U.S.is working very closely with Thailand's military government on the rescue.
Monday's operation took nine hours, two fewer than Sunday, with rescuers helped by the experience they have accumulated, Narongsak told a news conference punctuated with rounds of applause.
Four boys were extracted Monday, the Royal Thai Navy confirmed. The boys have reportedly yet to meet their families, though a senior official told The Guardian that they could be reunited on Monday night.
Cave rescue experts have said they consider an underwater escape to be a last resort, especially with people untrained in diving.
Rescuers have been unable to extend a hose pumping oxygen all the way to where the boys are, but have brought them some oxygen tanks.
A Royal Thai Police helicopter airlifts the fifth boy from a makeshift pad in Mae Sai district to Wing 416 in Muang district in Chiang Rai on Monday.
On Sunday, officials decided they could no longer wait, saying conditions were "as ideal as they will be" for a rescue attempt.
On Friday, the death of a former Thai navy SEAL underscored the risks.
Medical teams previously said concerns included hypothermia and an airborne lung infection known as "cave disease", which is caused by bat and bird droppings.
But the early signs on the initial eight were promising, with X-rays and blood tests showing just two had signs of pneumonia and that they were in a "normal state" after taking antibiotics, Jedsada said.
The only way to bring the boys and their coach out of the cave is by navigating dark and tight passageways filled with muddy water and strong currents, as well as oxygen-depleted air. I'm happy being here inside, the navy SEALS have taken good care.
The cave complex is off-limits during the rainy season, which usually runs from May to October, when downpours can quickly flood it.
And Gianna Infantino, the president of Federation Internationale de Football Association, soccer's governing body, has invited the boys to the World Cup final in Moscow on Sunday.