After a big spike in activity at the mouth of the cave, Reuters and the BBC are now citing officials saying the second rescue mission to retrieve more boys from the cave has begun.
On Sunday, chief of operations governor Narongsak Osatanakorn said 7 British, 6 Australian and five Thai divers are taking part in the operation.
It is the same team who successfully evacuated four boys on Sunday.
The British Cave Rescue Council (BCRC) confirmed that seven divers from the UK with “expertise in cave diving” are assisting.
Two elite British divers, Rick Stanton and John Volanthen, were the first rescuers to reach the group on Monday night and are believed to be leading the team, comprising British and Australian cave divers.
A BCRC spokesman said: “The UK divers are part of the core team, so they will be actively involved and that will include escorting each child out through the flooded passage.
“The operation is being supervised by the Thai authorities.
“They have had to make a quick decision because they are really concerned about the water level rising.”
Two divers were expected to accompany each boy as they are gradually extracted.
The entire operation to get all 13 out of the cave could take two to four days, depending on weather and water conditions, said Thai army Major General Chalongchai Chaiyakam.