Rescuers located 12 boys and their soccer coach alive deep inside a partially flooded cave in northern Thailand late Monday, more than a week after they went missing, bringing hope in a desperate search that has attracted international help and captivated the nation.
Chiang Rai provincial Gov. Narongsak Osatanakorn said the 13 were in the process of being rescued, but he cautioned that they were not out of peril yet.
"We found them safe. But the operation isn't over," he said in comments broadcast nationwide.
Rescue divers had spent much of Monday making preparations for a final push to locate the lost soccer players, aged 11 to 16, and their 25-year-old coach. They disappeared when flooding trapped them after entering the Tham Luang Nang Non cave on June 23.
Thai navy SEAL divers and rescue workers from other countries made initial progress through the narrow passageway early Monday after passing through a key chamber on Sunday whose high, murky waters had previously blocked their progress.
Narongsak earlier said the passageway the divers made their way through goes upward in some places and downward in others and is extremely narrow, making it difficult for divers with all their gear to fit through.
Divers have been stymied repeatedly by rising water that has filled sections of the cave and forced them to withdraw for safety reasons. When water levels dropped Sunday, the divers went forward with a more methodical approach, deploying a rope line and extra oxygen supplies along the way.
The SEALs' Facebook page said that since Sunday night, the divers had reached a bend where the kilometer-long (half-mile-long) passage splits in two directions. The divers were aiming for a sandy chamber on higher ground in the cave.
Narongsak explained earlier Monday that fixing rope lines and deploying oxygen tanks along their route will allow the divers to operate.
In addition to the divers, teams have been working to pump out water as well as divert groundwater. Other efforts have focused on finding shafts on the mountainside that might serve as a back door to the blocked-off areas where the missing may be sheltering.
Teams have been combing the mountainside looking for fissure that might lead to such shafts. 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.
Experts in cave rescues from around the world continued to gather at the site. An official Australian group has now followed a U.S. 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-strong U.S. military team assisting in the search operation, referring to the rain that has been flooding the cave. "So I'd say, yeah, it's an accurate statement that it's challenging."