Rescuers have punched a hole into the side of a mountain in a desperate attempt to drain rising water from to rescue a youth soccer team believed to be trapped in a Thailand cave for nearly a week.

US troops and British divers joined rescue efforts at Tham Luang cave during the fifth day of the search on Thursday.

However, the effort appeared unsuccessful as divers struggled to navigate passages filled with muddy water, with flood waters and heavy rain forcing them turn back.

“The water level is too high for the search team to go back in the cave. It almost reached the cave entrance now,” Interior Minister Anupong Paochinda told a press briefing on Thursday.

“It has now stopped raining, which is a good sign. The SEAL unit and divers from overseas are on stand-by as soon as it’s okay to go in.

“We are doing our best to drain out the flood.”

Rescuers are seeking alternative ways of entering the sprawling cave with plans to drill a hole into the cave on Friday, after dispatching drones yesterday to find an ideal site for the hole.

On Saturday, a dozen boys, aged 11-16, and their 25-year-old coach decided to visit the Tham Luang Cave after a training session in Chiang Rai provinces, 1000km north of Bangkok, near the border with Myanmar.

They have not been seen since.

Traces of their handprints and footprints found inside the cave are a sign they may still be alive, and were only trapped by a flash flood that blocked their way out, officials said. Rescuers have also discovered their backpacks.

Rescuers previously dived five metres into a large chamber in the cave suspected to be the group’s whereabouts, but found it empty. They believed the group walked further into the cave to avoid the flood.

“At the moment, the sad thing is we don’t know how far they have gone into the system,” said Vern Unsworth, a British cave explorer who explored the Thai cave before and is now assisting the search mission.

“Two kilometres in, you have a junction and you can go left or right. At the moment, we are assuming they’ve gone left because that is the main path of the cave.”

The suspension means up to 32 personnel from the US who arrived at the cave early on Thursday, and three British expert divers are currently on stand-by.

-with AAP