Australia's foreign affairs, defence and home affairs ministers said in a joint statement late on Saturday that Australia was working closely with the Thai government and the Royal Thai Army, who are leading the search operation.

The ADF has also deployed an official to the rescue command centre in Chiang Rai as a Specialist Liaison Officer to provide operations and planning expertise.

A Department of Foreign Affairs and Trade officer is also deploying with the AFP rescue team to assist with coordination.

The soccer team of 12 boys aged between 11 and 16, along with their 25-year-old coach, entered the Tham Luang Nang Non cave in Chiang Rai on June 23 but no contact has been made with them since.

Rescuers including Thai navy divers, a US military team and British cave experts have been hampered by incessant rain that has flooded the cave.

A private Chinese group, calling itself Green Boat Emergency, arrived on Saturday.  ‘‘Our skills are search and rescue on mountains and in caves. We hope we can help,’’ said Wang Xudong, a member of the group.

Chiang Rai Governor Narongsak Osatanakorn said the falling water level in the cave has helped the rescue effort considerably. ‘‘Today the situation is much better and we have high hopes, and will be here all night,’’ he said late on Saturday.

Thai navy SEAL divers have been crucial to the search, but have been stymied by muddy water reaching the cave’s ceiling, forcing them to suspend operations again and again.

With water levels dropping, they resumed dives on Saturday, re-entering a chamber from which they had retreated earlier in the week. In addition to pumping out the flooded chambers, there have been efforts to find the source of the water flooding the cave in order to drain or divert it.

Chaiwat Dusadeepanich of the Department of Groundwater Resources said on Saturday that his team, which has been drilling for two days, found a small underground water source near the cave. ‘‘But the water flow rate isn’t great enough,’’ he said. ‘‘We would have to drill in deeper to get to the source, but at least we found it. Hopefully we can start pumping out the well water by the end of today.’’

Hopes were also high for finding some kind of access through fissures on the mountainside that might lead to shafts into the cave. ‘‘Yesterday our team climbed into one shaft, and went in around 50 metres,’’ said National Deputy Police Chief Wirachai Songmetta. He said the shaft had led to two separate chambers so far.

AAP, AP