China and Australia have joined the search for 12 boys missing in a Thai cave, as divers on Sunday closed in on the spot they believe the teens are sheltering.
The international rescue operation -- which includes over 1,000 people from Thai emergency services, the US Military and British cave experts -- has been ramping up its efforts since the boys and their 25-year-old soccer coach disappeared during an outing in the caves in northern Thailand eight days ago.
Divers are now closing in on the spot where they believe the missing boys are sheltering in the Tham Luang Nang Non cave system.
The elevated dry area, called Pattaya Beach, is several kilometers from the entrance of the cave.
Water from the flooded cave has receded in recent days, allowing rescue teams to gain ground, according to Chiang Rai province governor Narongsak Osatanakorn.
Oxygen tanks have been installed at 25-meter junctures for divers to use, and a water pumping machine has also being deployed, added Osatanakorn.
Heavy rains had previously hampered the rescue operation, as the caves became extremely dark and muddy.
The terrain is tough going -- mountainous and heavily forested, slowing down teams looking for other possible points of entry, according to CNN meteorologist Derek Van Dam.
On Friday a team of six Chinese experts arrived at the site in Chiang Rai province, according to the Chinese Embassy in Thailand. The experts hail from the Beijing Peaceland Foundation, an organization with over 100 rescue teams and experience carrying out similar operations in mountainous Myanmar and Nepal.
On Saturday Australia also deployed a team of six experts from its national police's Specialist Response Group, according to the country's Minister for Foreign Affairs. The group, which typically carries out land search and rescue operations, also has experience diving in flooded caves.
For now, divers continue to work at the mouth of the cave, and drilling is underway at several points in the cave complex, primarily to relieve the flooding.
Anxious wait for families
The boys, all from the Wild Boars soccer teams and aged 11 to 16, have been missing since June 23, when a park officer spotted bicycles near the entrance to the off-limits cave complex.
The labyrinth is popular with tourists and for the first kilometer (0.6 miles) or so inside the cavernous entrance, limestone rock formations hug high ceilings, creating an almost amphitheater-like atmosphere.
Deeper inside, the passages narrow into places the locals warn it's not safe to go.
For reasons unknown, the boys and their coach ventured on, deeper into the cave network, past signs that warn people not to enter during the rainy season, which usually begins in July.
In the vigils that have grown with every day of fruitless searches, families and friends have prayed, made offerings, and held fast to the possibility of signs of life. Some, enduring the torture of such a long, silent wait, have collapsed in the mud with exhaustion, and been sent to a hospital.
"I feel I have just lost my heart when I found his bag, mobile phone and his shoes," said Prajak Sutham's father Sudsakorn. "But all I can do is wait."
Rescuers try other entry routes
Late last week trekkers discovered a hidden opening deep in the jungle that may be a new point of entry to the cave system.
The natural chimney, which is around 1.5 meters in diameter and at least 22 meters (72 feet) deep, was found to the north of the opening of the cave, where the boys' bikes were found last Saturday.
Approaching the tunnels from above is "more promising," according to British rescuers at the scene, as it bypasses a passage blocked by flood waters.
Two British cave experts entered the chimney Friday morning, managing to descend to a depth of about 20 meters, before being relieved by another team. Though this is not the first natural chimney found on Pha Mee, it remains the most promising, according to search and rescue teams on site.
Heat imaging drones are also being used to search the hilly terrain above the cave system.
Eight days after the boys went missing, rescue teams are remain optimistic that they closer than ever to finding them.