June 28 (UPI) -- The U.S. and British militaries have joined a search and rescue mission in Thailand for a dozen teen soccer players and a coach believed to be lost in a cave.
Heavy rains have interfered with the search for the missing team, forcing divers to turn back after waters flooded into a second chamber of the underground Tham Luang Nang Non cave complex in the Khun Nam Nang Non Forest Park in Chiang Rai.
"There's not much we can do right now," Thai Interior Minister Anupong Paojinda said. "We have to wait for the water level to decrease. Divers can't do anything right now."
A team of U.S. military rescuers arrived at the site Wednesday but weren't able to enter because of the flooding.
British cave experts Richard William Stanton, Robert Charles Harper and John Volanthen searched the cavern Thursday for about an hour.
"We've got a job to do," Volanthen said as he went into the tunnel.
The boys, aged between 11 to 16, and their 25-year-old coach have been missing in the caves since Saturday.
Authorities believe the team entered through a narrow 50-foot channel. The search began later that night.
Officials said there are roughly 40 chambers inside the complex, and rescuers believe the missing team is still in its main chamber. Rescuers are also looking for alternate passages.
"It seems the first option -- of drawing out water and bring them out through the mouth of the cave -- is difficult now," Chiang Rai Governor Narongsak Osatanakorn said. "We have another option, of going down from above. We found holes and chimneys, and we are prepared to drill the hole down if we have to."
The caves are located about 430 miles north of Bangkok and 30 miles south of the Thailand-Myanmar border.