Rescuers in Laos say they are investigating a possible “knocking response” deep inside a flooded cave network where two men are believed to remain trapped.
The development could indicate possible signs of life but rescuers stress they need to investigate further before saying for sure whether the knocks are from the stranded men.
The response sounds came as rescuers rappelled down a newly discovered vertical shaft that may provide a safer entry into a flooded cave and lead to a chamber where the men could be.
“We still cannot confirm that the knocking sounds came from trapped victims. However, we can confirm that there were definite knocking sounds in response to the signals,” Thai specialist cave diver Kengkard Bongkawong told CNN by phone on Monday.
Rescuers have now heard knocking responses on at least two occasions in the last 24 hours.
Thai rescue technician Manat Artmongkron posted on Facebook that the response was heard 70 meters (230 feet) down the shaft.
“The response was heard just 5 meters away, which is good news. We will update soon,” he wrote.
