Cave divers in northern Thailand have rescued four more boys from a vast flooded cave system, a source within the operation has told the BBC.
This suggests that, in total, eight boys have been safely brought out, while five people remain inside the caves.
The 12 boys and their football coach were trapped in the cave on 23 June after heavy rains caused flooding.
They were found alive last week by divers.
Four boys were brought out safely on Sunday, but the mission was paused overnight for air tanks to be replaced.
There has been no official confirmation from the Thai Navy Seals leading the rescue operation that anyone was brought out of the cave system on Monday, the second day of a complex operation.
Before the source told the BBC’s Jonathan Head that four more boys had been rescued in Monday, BBC teams saw air ambulances departing from the cave system and ambulances arriving at the hospital in the nearby town of Chiang Rai.
- Live updates on the rescue operation
- Who are the Thai boys trapped in a cave?
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Rescuers decided to go ahead with the operation to free the group because of fears that waters would rise again.
The rescue is complicated by sections in the cave involving diving – sometimes in a very confined space – and climbing.
Rescue mission chief Narongsak Osottanakorn said it had resumed at 11:00 local time (04:00 GMT) and would conclude at 21:00.
“More personnel” were being used than on Sunday, he added.
The names of the rescued boys have not been released out of respect for the families whose sons were still inside, and they have not been reunited with their own families, the mission chief said.
He said physical contact with loved ones would be avoided until a risk of infection had passed, though contact through glass or at a distance might be allowed.
Mr Narongsak allayed concerns that recent heavy rain might have raised water levels, saying conditions were “as good as yesterday”.
Rescuers took advantage of a break in the rain on Sunday to launch the mission earlier than some expected.
The first stage of the mission ran “smoothly” and the rescued boys were in “good health”, according to the Thai authorities.
How are the boys being moved?
A team of 90 expert divers – 40 from Thailand and 50 from overseas – has been working in the cave system.
They have been guiding the boys through darkness and submerged passageways towards the mouth of the Tham Luang cave system.
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