Eight of the 12 boys trapped with their soccer coach in a labyrinthine flooded cave complex in northern Thailand have been freed, authorities said on Monday, adding that the time for rescuing the others will depend on the weather.
Even as a massive operation is underway to rescue the remaining members of the Thai soccer team trapped in a flooded cave, a diver involved with the mission highlighted the risks involved in carrying out the rescue.
Narongsak said 13 foreign divers and five Thai navy SEALs took part in the key leg of Sunday's rescue: taking the boys from where they have been sheltering and through dark, tight and twisting passageways filled with muddy water and strong currents.
The rescue mission began on Sunday morning, almost a week since the 12 boys, aged 11-16, and their coach had been discovered on an embankment 2.5 miles (4 kilometers) inside the winding tunnels.
Narongsak said Monday's rescues involving 18 divers and a support team of 100 had taken nine hours, two fewer than the rescues on Sunday.
"Today (Tuesday) we hope to be faster", Narongsak added, of the complex and risky operation that involves diving through narrow, flooded chambers.
Thailand's health ministry permanent secretary Jesada Chokdamrongsuk told reporters that the first eight boys rescued from the cave complex are generally in good health and had asked for chocolate bread for breakfast.
Thai officials say four boys were brought out of a flooded cave in northern Thailand on Monday.
"Water levels are the same like the last two days", he said, adding that rescue efforts were expected to faster than they had been before.
The head of the operation, Narongsak Osottanakorn, said a final operation would be "more challenging" because one more survivor would be brought out than the previous two operations, along with three Navy SEALs who have been accompanying them.
Narongsak said two of the boys evacuated on Sunday emerged with lung infections, but their condition was improving with doses of antibiotics.
The second group freed on Monday were aged 12 to 14.
Officials will be meeting late Monday to discuss Tuesday's plan.
Some family members have been allowed to visit the boys in hospital, but are only allowed to observe them from behind a glass window. But they also warned heavy rain could hamper their efforts.
Technology billionaire Elon Musk went into the cave on Monday and left the rescue team with a "kid-sized" submarine his company SpaceX had built, Thailand's interior Minister Anupong Paochinda said.
Musk had offered mini submarine, named Wild Boar after the kids' football team, to help in the rescue operation.
He also tweeted videos of the sub being tested in a swimming pool in California with simulated narrow passages like the cave.
Divers are forced out of the cave by rushing floodwaters as they try to reach an air pocket called "Pattaya Beach", where the boys are believed to have retreated.