Family members of the missing cheered and hugged each other when they heard they had been found.
The children, who are aged between 11 and 16, had become trapped in the Tham Luang caves in Chiang Rai after heavy rain triggered a flash flood that prevented them escaping through a narrow tunnel.
A rescuer makes his way down muddy steps past water pump hoses at the entrance to a cave complex where 12 soccer team members and their coach went missing, on July 2, 2018, in Mae Sai, Chiang Rai province, in northern Thailand.
"Many people come." The divers provided the group with lights and told them food and medical help were on the way.
The rescuers then explain they have to leave but will return. They are seen wearing the same clothing they had on the morning they disappeared.
"The Seal unit last night reached the T-junction and today they will press ahead to the left, but one obstacle we've found is a very small hole which we need to widen so that people can go through", the governor said Monday.
"You've been here 10 days".
"If the children are to be brought out before then, they will have to learn basic diving skills to safely get through the risky corridors of muddy, zero-visibility waters as attempts to pump the water levels lower have so far not been successful", an Army official told BBC. "I'm not sure they can eat as they have not eaten for a while".
"How many are you?" Still the British Cave Rescue Council said: "Any attempt to dive the boys and their coach out will not be taken lightly because there are significant technical challenges and risks to consider". "Trying to take non-divers through a cave is one of the most unsafe situations possible, even if the dives are relatively easy".
"They'll be assessed for hydration status, adequate fuel supply, adequate food so that their glucose level is adequate, and then no doubt they'll do practice dives", he added.
Prime minister Prayuth Chan-ocha thanked global experts and rescuers who helped the search.
The worldwide rescue operation - which includes the Thai Navy SEALs as well as experts from the US, China, Australia and the United Kingdom - had been working to reach a large, deep chamber, informally known as Pattaya Beach, where the missing boys were believed to have taken refuge.
The passageways that lead to the group are extremely narrow, making it hard for divers and their gear to fit through.
Expert divers said they had made progress earlier on Monday after reaching a bend where a half-mile passageway splits into two directions. "It is another high ground", Osottanakorn said of where the group was located.
"Worst case scenario is they have to dive them out", said Pat Moret, a rescue consultant told CNN on Monday.
Though the opening did not connect to area where the boys were discovered, now that the boys' location is known, rescue efforts can focus on finding other, potentially hidden openings.
Cochrane said thousands of soldiers have been scouring the mountain looking for ventilation shafts that could provide a back door to the cave. Several have been found and explorers have been able to descend into some, but so far it is not clear whether they lead to anywhere useful.
But one cave rescue expert was cautious about this approach. An official Australian group has followed a USA military team, British cave experts, Chinese lifesaving responders and several other volunteer groups from various countries.
"These are challenging conditions and there's a lot of consideration for safety as well as, the environment outside is contributing to the environment inside", said U.S. Air Force Capt. Jessica Tait, part of a 30-member U.S. military team assisting in the search, referring to the rain that has been flooding the cave.