MAE SAI, Chiang Rai: All 12 boys and their football coach trapped in Tham Luang cave for 17 days have been safely rescued.

“The 9th Wild Boar was out of the cave at 4.06pm,” the Thai Navy Seals posted on Facebook on Tuesday, the projected final day of the mission.

A source said the 10th came out shortly afterwards, followed by the 11th and 12th at 6.25pm. Their 25-year-old football coach was the last to come out. They are recovering in hospital.

Meanwhile, Prime Minister Prayut Chan-o-cha denied rumours on Tuesday that the boys had been drugged to facilitate the operation, saying the children had not been given anaesthetic. 

"Who the hell would give that to a kid?" he said before clarifying that they had been given something to calm their nerves and prevent them from panicking.

Earlier on Tuesday, rescue leader governor Narongsak Osatanakorn said divers were carrying out what they hoped would be a final mission to save the four boys and their soccer coach trapped in a flooded cave for more than two weeks, as health experts gave the eight already brought out a chocolate treat and described them as being in good spirits.

The rescue chief said Tuesday's intricate and high-risk operation began just after 10am and involved 19 divers. A doctor and three Thai Navy Seals who had stayed with the boys on a small, dry shelf deep in the flooded cave would also come out.

The first eight boys brought out by divers are in “high spirits” and have strong immune systems because they are soccer players, a senior health official said.

Doctors were being cautious because of the infection risk and were isolating the boys in the hospital. They did get a treat of bread with chocolate spread that they'd requested.

The plight of the boys and their coach has captivated the world -- from the heart-sinking news they were missing to the first flickering video of the huddle of anxious yet smiling boys when they were found 10 days later by a pair of British divers. They were trapped in the Tham Luan Nang Non cave after it became flooded by monsoon rains while they were exploring it after a soccer practice on June 23.

At a news conference, Jedsada Chokdumrongsuk, permanent secretary at the Public Health Ministry, said the first four boys rescued, aged 12 to 16, are now able to eat normal food. Two of the boys may have a lung infection but all eight are generally healthy and smiling, he added.

“The kids are footballers so they have strong immune systems,” Dr Jedsada said. “Everyone is in high spirits and are happy to get out. But we will have a psychiatrist evaluate them.”

It could be at least seven days before they can be released from hospital, he told a news conference.

Family members have seen at least some of the boys from behind a glass isolation barrier. Dr Jedsada said doctors may let the boys walk around their beds on Tuesday. Doctors have been cautious because they are uncertain what type of infections the boys could be vulnerable to “because we have never experienced this kind of issue before.”

If medical tests show no danger, after another two days parents will be able to enter the isolation area dressed in sterilised clothing and stay 2 metres away from the boys, said Tosthep Bunthong, Chiang Rai Public Health Chief.

At least nine ambulances and a convoy of other vehicles were at the cave site Tuesday. Heavy rains in the morning cleared during the day, a reassuring sign for rescuers who feared monsoon rains could imperil the rescue.

Officials decided against using tech billionaire Elon Musk's mini-sub made of rocket parts to rescue the remaining boys. Mr Narongsak said he was grateful for Mr Musk's support but the equipment was impractical for the rescue mission.

Mr Musk on Tuesday visited the cave and posted pictures and videos online. He said he left the equipment there in case rescuers could use it in the future.