The ambulances then drove to a nearby helipad, and a helicopter which had been deployed there to take any extracted youngsters to hospital was seen taking off.
"We've been working continuously overnight", a Chiang Rai government source told AFP on Monday morning, requesting anonymity, and confirming that there had only been a pause of the actual extraction operations. The interior minister Anupong Paojinda was noted saying that officials are meeting on Monday morning to plan the next stage of the operation in order to rescue the remaining 9 students from the cave.
He said the healthiest were taken out first, and the next phase of the operation would start in 10-20 hours.
The boys urged relatives "not to worry" and asked for their favourite food once they were safely evacuated, in notes handed to divers. He has also thanked global experts who helped find the boys. "We have been practising for the past three to four days, rain or shine".
Mild weather and falling water levels over the past few days created optimal conditions for an underwater evacuation, but that won't last if it rains again, Narongsak said.
The four boys pulled from the cave Sunday in an urgent and unsafe operation that involved them diving through the cave's dark, tight and twisting passages were happy and in good health, authorities said.
He said the next operation will be conducted on Tuesday.
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The boys and their coach went exploring in the massive Tham Luang Nang Non cave on June 23 after a soccer practice, and were cut off when a rainstorm flooded the cave.
The rescue mission is expected to take another two to four days. Apart from the Thai authorities, 19 Australian divers are a part of the unsafe rescue mission.
Meanwhile rescuers fed a kilometres-long air pipe into the cave to restore oxygen levels in the chamber where the team was sheltering with medics and divers. Trips from the entrance to where the team is trapped and back to the entrance take about 11 hours.
The Thai Navy SEAL's Facebook page reports the third boy was rescued from the cave at 7:35pm, local time.
"Light enough to be carried by 2 divers, small enough to get through narrow gaps". Mr Narongsak would not say which of the boys were rescued.
The death Friday of a former Thai navy SEAL underscored the risks.
Divers have been guiding the boys through darkness and submerged passageways towards the mouth of the cave.
Officials had estimated that the first boy would emerge only at 9pm - but the boys beat expectations.
The other, and perhaps more worrying, was that oxygen levels in the complex were falling close to unsafe levels.