The moment British divers exclaim 'brilliant' as they find 12 boys and coach still alive in Thailand cave

Video footage showing the 12 young Thai boys and their football coach who have been missing in a cave in Thailand for more than a week has emerged.

British divers are heard exclaiming "brilliant" as the group confirm all 13 are alive underground.

The conversation lasts around a minute as the boys, aged between 11 and 16, describe their plight trapped on a muddy bank inside the cave.

The boys and their 25-year-old coach went missing in the Tham Luang Nang Non cave in Thailand's Chiang Rai province on June 23.

On Monday, after more than a week of searching by an international rescue team, they were found alive.

Narongsak Osatanakorn, governor of Chiang Rai province, said the 13 were in the process of being rescued, but cautioned that they were not out of danger yet.

"We found them safe. But the operation isn’t over," he said.

Heavy rain that flooded key passages within the caves is believed to have left the group trapped.

Search teams have been repeatedly hampered by rising muddy water forcing divers to withdraw.

But earlier navy divers and rescue workers entered a narrow passageway, having passed through a key chamber on Sunday whose high, murky waters had previously blocked their progress.

Rescuers then went forward with a more methodical approach, deploying a rope line and extra oxygen supplies along the way.

Chiang Rai Governor Narongsak Osatanakorn announces the team have been found alive:

The Chiang Rai governor Mr Narongsak said the passageway the divers were making their way through goes upwards in some places and downwards in others and is extremely narrow, making it difficult for divers to fit through with all their gear.

He said the divers located the missing about 300-400 meters past a section of the cave that was on higher ground and was thought to be where the team members and their coach may have taken shelter.

He said it was expected that in their condition, the boys would at first not be able to move their limbs, but medical teams would initially treat them in place. He said the diving teams included doctors.

Nonetheless, family members of the missing hugged each other as they cheered the news the 13 had been found.

Aisha Wiboonrungrueng, the mother of one of the boys, 11-year-old Chanin, smiled and hugged her family. She said she would cook her son a Thai fried omelet, his favorite food, when he returns home.

Rescuers have reached the trapped children and their coach

Prime minister Prayuth Chan-ocha thanked international experts and rescuers who helped the search.

His office said the PM “wishes to thank the tremendous efforts of all international units that have come to assist the Thai authorities in rescuing the youth football team that was stuck in the caves in Chiang Rai.

"The Royal Thai Government and the Thai people are grateful for this support and co-operation, and we all wish the team a safe and speedy recovery”.

Among the groups to join the Thai Navy Seals in the more than week-long rescue was an Australian and US military team, British cave experts, and Chinese lifesaving responders.

Relatives have been praying for a successful rescue Credit: AP

Anmar Mirza, a leading American cave rescue expert, said many challenges remain for the rescuers. He said the primary decision is whether to try to evacuate the boys and their coach or to supply them in place.

"Supplying them on site may face challenges depending on how difficult the dives are," Mirza, coordinator of the US National Cave Rescue Commission, said in an email.

"Trying to take non-divers through a cave is one of the most dangerous situations possible, even if the dives are relatively easy. That also begets the question: If the dives are difficult then supply will be difficult, but the risk of trying to dive them out is also exponentially greater."