"The eighth person is out and the operation is done for today", Sitthichai Klangpattana, flag officer to Thailand's Navy SEAL commander, told The Associated Press. They wore full-faced masks "while hanging on to the bodies of rescue divers", Channel News Asia reported.
As of Monday morning, nine people remained trapped in the cave, including the 12-member team's coach, after four boys were rescued on Sunday, the first day of the rescue operation.
Four other youngsters and their soccer coach are still inside.
Still, for the relatives of the Wild Boar team members, an agonising wait continued.
The daring and unsafe 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. "Hooyah", the Thai Navy SEALS wrote on their Facebook page Monday, referring to the boys' soccer team, the Wild Boars.
He told reporters the four rescued boys were taken to the hospital in the town of Chiang Rai, the provincial capital, for evaluation, and the next phase of the operation would resume after about 10-20 hours. Though they'll mostly be eating a food similar to milk and rich in proteins and nutrients.
It's a process that can take several hours.
British divers Rick Stanton and John Volanthen were the first to reach them 2.5 miles into the cave, just past Pattaya Beach.
The rescue teams are still packing up after their mammoth task to pull the boys out. "We have to quarantine them for a little while due to fear of infection".
The second group freed on Monday were aged 12 to 14.
"The kids are footballers so they have high immune systems", Jesada said.
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.
Shortly after the news of the boys' safe return broke, US President Donald Trump tweeted his congratulations to the Navy SEAL team. Each of the rescued boys has been guided through the dark winding cave by a pair of divers. "Such a attractive moment - all freed, great job!"
He said that water level in the cave continued to recede, facilitating the rescue operations five hours early on Monday. "We achieved a mission impossible". The lower the water is getting, the stronger the current.
The submarine is small and light enough to be carried by two divers, and can navigate through the narrow submerged areas in the cave, which is said to be the biggest challenge in rescuing the children trapped in the cave.
"We can only see our hands (at a) short distance".
The most unsafe part of the journey out of the labyrinth cave system is the first kilometer, during which they are required to squeeze through a narrow flooded channel. Rescue officials say that at this point, rain is not an issue, but that could change in the coming days.
Heavy rain soaked the area overnight, increasing the risks in what has been called a "war with water and time" to save the boys.
Four more boys were rescued on Monday, after the first four were rescued on Sunday.
He had said fresh air tanks needed to be laid along the underwater route. Efforts to pump water out of the cave have been set back by heavy downpours.
The condition of the boys and rescuers is unknown at this time.
Families have not been told which boys are free, so all parents have agreed to remain at the cave until the entire team is rescued.