US military joins search for missing boys in Thailand cave as rescue shifts to hunt for other entrances

The attempted rescue of a dozen boys and their soccer coach after a heavy rainstorm flooded the entrance to a popular cave in Thailand has turned into a hunt for another entrance, as U.S. military and British cave expects joined the search on Thursday.

Heavy rain has hampered the search and some of the rescue divers have been forced to turn back after floodwater seeped into a second chamber of the caves, five days after the group was reported missing.

"There's not much we can do right now," Interior Minister Anupong Paojinda told reporters. "We have to wait for the water level to decrease. (Divers) can't do anything right now."

U.S. Special Operations Command Pacific Search and Rescue team personnel walk out of a cave where a young soccer team and their coach are believed to be missing, Thursday, June 28, 2018, in Mae Sai, Chiang Rai province, in northern Thailand. A U.S. military team and British cave experts joined the rescue effort for 12 boys and their soccer coach missing for five days inside the cave being flooded by near-constant rains. (AP Photo/Sakchai Lalit)

U.S. Special Operations Command Pacific Search and Rescue team personnel walk out of a cave where a young soccer team and their coach are believed to be missing in northern Thailand.  (AP Photo/Sakchai Lalit)

The setback in the search due to rising water levels comes as Thai rescuers have been joined by a U.S. military team and British cave experts. Deputy Prime Minister Prawit Wongsuwan said 30 members of the United States Pacific Command (USPACOM) have joined the search operation, according to Reuters.

Tony Haigh, the British Cave Rescue Council's communications officer, told Sky News that divers are used to diving in the challenging conditions found in many U.K. caves, and can conduct dives in low visibility conditions and in small passages.

U.S. Special Operations Command Pacific Search and Rescue team personnel walk in a cave where a young soccer team and their coach are believed to be missing, Thursday, June 28, 2018, in Mae Sai, Chiang Rai province, in northern Thailand. A U.S. military team and British cave experts joined the rescue effort for 12 boys and their soccer coach missing for five days inside the cave being flooded by near-constant rains. (AP Photo/Sakchai Lalit)

U.S. Special Operations Command Pacific Search and Rescue team personnel walk in a cave where a young soccer team and their coach are believed to be missing.  (AP Photo/Sakchai Lalit)

YOUTH SOCCER TEAM TRAPPED IN THAILAND CAVE AFTER RAINSTORM

The cave complex extends several miles and has wide chambers and narrow passageways with rocky outcrops and changes in elevation. Still, officials have said they are hopeful the boys found a safe space away from the floods.

The chamber is about 2.5 miles from the entrance of the cave, which is thought to be about 4-5 miles long and cut into a mountainside in far northern Thailand near the border with Myanmar.

Rescue personnel walk out of the entrance to a cave complex where it's believed that 12 soccer team members and their coach went missing, Thursday, June 28, 2018, in Mae Sai, Chiang Rai province, in northern Thailand. A U.S. military team and British cave experts joined the rescue effort for 12 boys and their soccer coach missing for five days inside the cave being flooded by near-constant rains. (AP Photo/Sakchai Lalit)

A U.S. military team and British cave experts joined the rescue effort for 12 boys and their soccer coach missing for five days inside the cave being flooded by near-constant rains.  (AP Photo/Sakchai Lalit)

Deputy national police Chief Wirachai Songmetta told the Associated Press he would join more than 600 rescuers above ground scouring a mountainside trying to find shafts that might be possible entrances into the cave.

"We won't give up. That's the key here," he said as he got into a vehicle that was part of a convoy carrying rescuers.

Rescue personnel walk out of the entrance to a cave complex where it's believed that 12 soccer team members and their coach went missing, Thursday, June 28, 2018, in Mae Sai, Chiang Rai province, in northern Thailand. A U.S. military team and British cave experts joined the rescue effort for 12 boys and their soccer coach missing for five days inside the cave being flooded by near-constant rains. (AP Photo/Sakchai Lalit)

A U.S. military team and British cave experts joined the rescue effort for 12 boys and their soccer coach missing for five days inside the cave being flooded by near-constant rains.  (AP Photo/Sakchai Lalit )

SEARCH FOR YOUTH SOCCER TEAM TRAPPED IN THAILAND CAVE COMPLICATED BY MORE FLOODING

Some parents of the missing children have been spending the nights in tents outside the cave entrance as the rain poured.

On Thursday morning, a Buddhist monk led a prayer for a small group of relatives waiting outside for any news.

U.S. Special Operations Command Pacific Search and Rescue team personnel walk out of a cave where a young soccer team and their coach are believed to be missing, Thursday, June 28, 2018, in Mae Sai, Chiang Rai province, in northern Thailand. A U.S. military team and British cave experts joined the rescue effort for 12 boys and their soccer coach missing for five days inside the cave being flooded by near-constant rains. (AP Photo/Sakchai Lalit)

U.S. Special Operations Command Pacific Search and Rescue team personne; walk out of a cave where young soccer team and their coach are believed to be missing, Thursday, June 28, 2018, in Mae Sai, Chiang Rai province, in northern Thailand.  (AP Photo/Sakchai Lalit)

“Observe your breath in this place of love. Love between mother, father and child,” the monk told relatives outside, according to Reuters. “Do not worry and wait for good news.”

The Associated Press contributed to this report.

Travis Fedschun is a reporter for FoxNews.com. Follow him on Twitter @travfed