Miracle on hold

Four boys among a group of 13 trapped in a flooded Thai cave for more than a fortnight were rescued yesterday after surviving a treacherous escape, raising hopes elite divers would also save the others soon.

The rescued boys emerged as night fell from the Tham Luang cave complex after divers guided them along a route of more than four kilometres (2.5 miles) that included twisting, extremely narrow and jagged passageways filled with water.

Their escape led to an explosion of jubilation on social media in Thailand as the rescued boys were rushed to hospital.

But the survival of those remaining in the cave is far from guaranteed with extraction efforts put on hold until this morning to allow rescue divers time to resupply.

Rescue chief Narongsak Osottanakorn said the four who escaped were "safe", although there were few other details released about their condition on identities.

A defence ministry official had earlier told AFP six boys had made it out. But Narongsak and the Thai Navy SEALS -- who are involved in the rescue and have regularly posted updates about the operation on their Facebook page -- reported only four were out of the cave.

The group became trapped in a cramped chamber deep inside Tham Luang in a mountainous area of northern Thailand on June 23, when they went in after football practice to explore and got caught behind rising waters after a torrential downpour.

Their plight transfixed Thailand and the rest of the world, as authorities struggled to locate them and then devise a plan to get the boys -- aged between 11 and 16 -- and their 25-year-old coach out.

The group was found dishevelled and hungry by British cave diving specialists nine days after they ventured in.

Initial euphoria over finding the boys alive quickly turned into deep anxiety as rescuers struggled to find a way to get them out.

The death of a former Thai Navy SEAL diver who ran out of oxygen in the cave on Friday underscored the danger of the journey even for professionals.

'D-DAY'

Foreign elite divers and Thai Navy SEALS were forced to begin the complex operation to extract the earlier than they had hoped yesterday morning because forecast rainfall was threatening more flooding that might doom the mission.

"Today is the D-day. The boys are ready to face any challenges," Narongsak told reporters near the cave site yesterday morning.

"There is no other day that we are more ready than today," he said. "Otherwise we will lose the opportunity."

The rescue of the initial batch of boys was a stunning victory in an operation Narongsak had earlier dubbed "Mission Impossible" and led to cautious optimism that the others would also be saved.

Narongsak described the extraction of the initial group of four as "smooth".

But efforts to get the others out were put on hold until this morning to give rescue workers time to replenish stocks of oxygen and other supplies.

"We need to refill," Narongsak said.

TREACHEROUS JOURNEY

Between the base camp operated by Thai Navy SEALS inside the cave and the trapped boys are twisting passageways with torrents of water gushing through.

The water in the cave is muddy and unclear, with one diver comparing it to a cafe latte. Ropes have been installed to help guide the boys through the darkness.

Narongsak said yesterday morning two divers would escort each of the boys, none of whom had previous scuba diving experience, out of the cave.

Authorities had looked at many different ways to save the boys and their coach.

One early potential plan was to leave them there for months until the monsoon season ended and the floods subsided completely, but that idea was scrapped over concerns about falling oxygen levels and waters rising too high.

More than 100 exploratory holes were also bored into the mountainside in an attempt to open a second evacuation route and avoid forcing the boys into the dangerous dive.

American technology entrepreneur Elon Musk even deployed engineers from his private space exploration firm SpaceX and Boring Co. to help.

Meanwhile rescuers fed a kilometres-long air pipe into the cave to restore oxygen levels in the chamber where the team was sheltering with medics and divers.

Thais were quick to jump onto social media on Sunday night to celebrate the rescue of the initial four.

"The rescue team of the Wild Boars should be given this year's World Cup trophy," one person wrote on Facebook, referring to the boys by the name of their football team.