Authorities are preparing to resume the rescue operation of the remaining eight boys and their football coach trapped in a flooded cave in Thailand.
The operation was paused as rain in the Chiang Rai region threatened to raise water levels inside the Tham Luang Nang Non cave again after four of the boys were brought to the surface on Sunday.
A heavy but brief downpour hit the area on Monday morning, but it was unclear how the rain affected the conditions inside the cave where the 12 boys and their coach were stranded by the high water more than two weeks ago.
New oxygen tanks are being placed in the cave before the second stage of the rescue effort can begin.
Extracting everyone from the cave could take up four days, but Sunday’s success raised hopes that could be done.
READ MORE: Thailand cave rescue: Six boys rescued as operation gets underway
Thailand’s interior minister Anupong Paojinda said the same divers who took part in Sunday’s rescue will return to extricate the others as they know the cave conditions and what to do. He said the boys rescued on Sunday were strong and safe but needed to undergo medical checks.
The British Cave Rescue Council (BCRC) confirmed that seven divers from the UK with “expertise in cave diving” are assisting.
Two elite British divers, Rick Stanton and John Volanthen, were the first rescuers to reach the group and are believed to be part of the team.
A BCRC spokesman said: “The UK divers are part of the core team, so they will be actively involved and that will include escorting each child out through the flooded passage.
“The operation is being supervised by the Thai authorities.
“They have had to make a quick decision because they are really concerned about the water level rising.”
Thai Prime Minister Prayuth Chan-ocha was scheduled to visit the site later on Monday, after first travelling south to Phuket, where a boat capsizing resulted in 42 deaths, mostly tourists from China.
“The operation went much better than expected,” Chiang Rai acting governor Narongsak Osatanakorn, who is overseeing the mission, said on Sunday night.
Two divers accompanied each of the boys, all of whom have been learning to dive only since July 2, when the first searchers found them.
Cave rescue experts consider an underwater escape to be a last resort, especially with people untrained in diving.
READ MORE: Thai Cave rescue described as ‘one of the greatest in history’
The death on Friday of a former Thai navy Seal, Saman Gunan, underlined the risks. The diver, the first fatality of the rescue effort, was working in a volunteer capacity and died on a mission to place oxygen canisters along the route.
Mr Narongsak said ahead of the rescue dive that recent mild weather and falling water levels had created optimal conditions for an underwater evacuation. He said those conditions will not last if the rain resumes.
After the four boys were removed from the cave, heavy rain started falling.
The potential for rising water and the dwindling oxygen levels added to the urgency of getting the team out. Efforts to pump water out of the cave have been set back by heavy downpours.
Mr Narongsak said that experts told him new rain could shrink the unflooded space where the boys are sheltering to just 10 square metres.
On Sunday night, Thai navy Seals posted a celebratory note on their Facebook page, saying: “Have sweet dreams everyone. Good night. Hooyah.”
The boys and their coach, whose team is known as the Wild Boars, became stranded when they were exploring the cave after a practice game on June 23.
Monsoon flooding cut off their escape route and prevented rescuers from finding them for almost 10 days.
The ordeal has riveted Thailand and captured the world’s attention. The search and rescue operation has involved dozens of international experts and rescuers, including a US military team.
Elon Musk’s Space X rocket company is testing a “kid-sized submarine” that could be sent to help boys trapped in a flooded Thailand cave.
Mr Musk posted videos on Twitter of the aluminium sub being tested at a swimming pool. If the tests were successful, the sub was to be placed on a 17-hour flight to Thailand.
A spokesman for Mr Musk’s Boring Co tunnelling unit, which has four engineers at the cave, has said Thai officials requested the device, which could potentially help the children through narrow, flooded cave passageways. However, it is unclear if the device is part of any current rescue plans.
US President Donald Trump tweeted 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. Very brave and talented people!”