Four more boys have been airlifted to a Chiang Rai hospital after they were safely brought out of the Tham Luang cave by the same team of elite divers who managed to rescue the first four boys on Sunday, according to the Thai Navy Seals.
The boys brought out of the dark, winding cave on Monday are "safe and conscious," he told the media.
The Seals posted a count on their Facebook page, concluding with "Two days, eight boars", a reference to the name of the boys' football team.
They were taken to Chiangrai Prachanukroh Hospital where their four teammates rescued on Sunday had been tested and waiting for an all-clear.
Monday's operation began at 11am and took nine hours, two fewer than Sunday, with rescuers helped by the experience they've accumulated, said Narongsak Osotthanakorn told a news conference punctuated with rounds of applause.
"We have more operating personnel. And we have more expertise than yesterday," he said.
Rescuing the remaining five people, including the boys' 25-year-old soccer coach, could take more than one operation, he said.
Authorities have not revealed at this stage when the rescue operation would resume for the remaining four boys and their coach, who have been trapped in the cave since June 23.
Prime Minister Prayut Chan-o-cha plans to host a thank-you party for all the rescue teams, Mr Narongsak said.
The premier arrived late Friday at the mouth of Tham Luang cave. Spokesmen said the purpose of the visit was "to give moral support to the rescue team members".
He later visited the eight rescued boys at the Chiangrai Prachanukroh Hospital.
Earlier in the day, the prime minister had visited Phuket to check on the search operation of tourists who were missing after a boat capsized off the resort island's coast on Thursday.
Describing Monday's rescue, the first source said the boys arrived at Chamber 3 at 4pm after being rescued by foreign and Navy Seal divers from the ledge called Nern Nom Sao, where they had sheltered from floodwaters for more than a week.
They were the second batch to undertake the perilous journey out of Tham Luang cave in Mae Sai district in Chiang Rai, after the first, weakest four left on Sunday in a similarly successful extraction.
Divers took about four hours to escort Monday's fortunate four from the ledge to the chamber, the source added.
Chamber 3 is the operational base for rescuers inside the cave. It is about two kilometres from the entrance. The evacuation procedure calls for the boys to receive initial medical treatment there before rescuers take them through the remaining stretch of the cave to a field hospital outside, and then transport them by helicopter or ambulance to join their colleagues at the hospital.
Rescue mission chief Narongsak on Monday said the operation on the second day started at 11am.
Four more young footballers and their coach at the Mu Pa (WIld Boar) Academy Mae Sai, Ekkapol Chantawong, are still on the ledge.
The thirteen were trapped by floodwater after entering the cave on June 23, and forced deeper and deeper inside the labyrinthine tunnels.