The complex, flooded Tham Luang cave system is posing challenges to the rescue.
Eight boys and their soccer coach who remain trapped in a flooded cave in northern Thailand waited for a rescue operation to resume on Monday as the first four unidentified boys freed were said to be in good health and recovering in hospital.
The daring and dangerous bid to rescue the boys - aged between 11 and 16 - was suspended by the mission chief late on Sunday to replenish oxygen supplies and make new preparations, which he said would take at least 10 hours.
Authorities have said the mission could take three or four days to complete.
Divers had to hold the first four boys close to their bodies to bring them out and each had to wear an oxygen mask to enable normal breathing, authorities said.
Bursts of heavy rain soaked the Tham Luang Cave area in Thailand's northern Chiang Rai province overnight, increasing the risks in what has been called a "war with water and time" to save the boys.
Rescue operations will resume today after a 10 hour hiatus.
Interior Minister Anupong Paochinda told reporters the rescued boys were in good health in hospital but did not give further details.
Authorities have not confirmed the identities of the first four boys freed. Some of the boys' parents told Reuters they had not been told who had been rescued and that they were not allowed to visit the hospital.
The head of the rescue mission, Narongsak Osottanakorn, said last week they would bring the fittest people in the group out first.
Somboon Sompiangjai, 38, the father of one of the trapped boys, said parents were told by rescuers ahead of Sunday's operation the "strongest children" would be brought out first.
"We have not been told which child has been brought out ... We can't visit our boys in hospital because they need to be monitored for 48 hours," Somboon told Reuters.
"I'm hoping for good news today," he said.
'Not bad'
At least nine ambulances loaded with stretchers and blue oxygen tanks waited in the cave area on Monday. The mood was fairly relaxed among the soldiers, medics, engineers and volunteers in yellow shirts that milled around.
"I feel very happy, everybody is happy," said Hnin Jaiwong, the mother of one of the trapped boys, 13-year-old Sompong Jaiwong.
"I don't know if he is out, they didn't tell us," she said as she rested in a hut close to the mouth of the cave.
A source inside the Chiang Rai Prachanukroh hospital where the first four boys are being kept said their condition was "not bad" but doctors were watching for signs of emerging conditions such as hypothermia.
The boys set out to explore the vast Tham Luang cave, which is known in the area as off-limits, after soccer practice on June 23. They were discovered huddled on a muddy bank by British divers a week ago.
Relatives say the boys had been inside the cave during the dry season, when the labyrinthine complex is easier to navigate.
The story of the "Wild Boars" soccer team has gripped Thai and international media.
After the boys were located, they were able to communicate to their family through letters
"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 currently underway in Russia.
The president of soccer's governing body, FIFA, has invited the boys to the World Cup Final in Moscow on Sunday if they make it out in time.
'Night and day'
Thirteen foreign divers and five members of Thailand's elite navy SEAL unit are the main team guiding the boys to safety through narrow, submerged passageways that claimed the life of a former Thai navy diver on Friday.
Some of the boys are not strong swimmers and none has diving experience.
Prime Minister Prayuth Chan-ocha, leader of the Thai military junta that seized power in 2014, planned to visit the cave site on Monday.
He addressed the rescue mission on Monday at the unveiling of a new project in Bangkok, where reporters asked him how many days it would take to get the boys out.
"Nobody can answer this," he said. "I am following this story 24 hours a day, night and day."
A short official video released by the rescue operation late on Sunday showed four ambulances with their lights flashing driving up the muddy dirt track that leads to the cave complex.
The 4 Thai boys who were rescued were taken to the hospital yesterday
It also showed about six soldiers carrying a stretcher towards a waiting ambulance. The stretcher was loaded into the back of the ambulance as medics rushed in the side door.
Narongsak was then seen shaking hands with a senior army figure and watching intently at the entrance of a long green medical field tent beside around 15 soldiers.
© Thomson Reuters 2018
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