Several ambulances were seen leaving the rescue site at around 12:40 p.m. local time, although it was unclear if the boys were inside.
The rescued boys are still being held in quarantine while lab tests are being done and have not been able to have direct contact with their parents yet.
Officials said all eight of the boys rescued so far were "good physically and mentally", though two of the four brought out on Monday had swollen lungs. That left four boys and the team's coach trapped inside as the operation was called off for the day.
The youngest member of the Wild Boar team in the cave is just 11 years old.
The boys underwent x-rays and blood tests and two who had signs of pneumonia were given antibiotics and are in a "normal state", he said, adding they will all remain under observation in hospital for a week.
"The machine has already been delivered to Thailand and ready to use in the rescue operation in a partially flooded cave Khao Luang", - he wrote. Rescue officials were hopeful that the final four boys and their coach would be rescued Tuesday.
Last week, Musk sent engineers from two of his companies, SpaceX and Boring Co., to assist Thai officials in the rescue effort, which comprises a large team of global diving, engineering and medical experts, among other professionals. The eight boys brought out on Sunday and Monday were in good health overall and some asked for chocolate bread for breakfast, officials said.
"Early this morning Harry's father passed away here in Adelaide. after they'd all come out of the cave", said Andrew Pearce, of the MedSTAR rescue service.
The eight boys rescued after being trapped for more than two weeks were described as generally healthy. Doctors were being cautious because of the infection risk and were isolating the boys in the hospital. "We have set the plan for four people so if they want to take five out (at the same time), then they need to change the plan". The team was trapped in a cave system after heavy rains forced them deeper into the caves in search of higher ground.
The search and rescue operation has riveted people both in Thailand and internationally, with journalists from across the globe travelling to this town along the border with Burma to report on the ordeal.
Elon Musk, the billionaire owner of Tesla and SpaceX, was in Thailand with engineers from his companies to offer their expertise in the rescue. "Hopefully useful. If not, perhaps it will be in a future situation".