A lack of oxygen in the 700-meter mine is hampering efforts to rescue four miners who remain trapped inside.
More than 300 people were evacuated after a dam burst on Monday. Locals say departmental negligence resulted in the breach.
Waste pile collapses in the region continue to threaten the lives of prospectors.
The soccer team and coach paid tribute to the ex-Navy SEAL who lost his life during a dramatic rescue operation at the Tham Luang cave complex.
The explosion comes amid a drive to strengthen industrial safety in the wake of some high-profile incidents at coal mines and chemical plants.
The first video of the Thai boys rescued from a flooded cave after 17 days was released, showing them smiling and waving from their hospital beds.
PM Shinzo Abe headed for the flood-stricken western part of Japan as the death toll from the worst weather disaster in 36 years passed 160.
Thais reacted with relief, gratitude and exhilaration after the successful rescue of the last group of 12 boys and their soccer coach from a flooded cave complex.
A government official said the first eight boys rescued from the cave were doing well but added that two of them may have developed lung infections.
A tenth person was rescued from a flooded cave where 12 boys and their soccer coach were trapped for over two weeks, raising hopes all 13 would be out by the end of the day.
Rescuers resume preparations for a third rescue operation to free four remaining boys and their soccer coach in a race against time and monsoon weather.
Monarch visits Shan monk, whom many in Thailand believe favorably affected outcome of the two-week saga.
Richard Harris undertook the dangerous dive to reach the 12 trapped boys and their coach and gave the final approval on their health, clearing the way for Sunday's rescue attempt.
Rescuers in Japan dug through mud and rubble, racing to find survivors after rains unleashed widespread floods and landslides that killed nearly 100, with dozens missing.
Four of 12 Thai schoolboys were rescued from a flooded cave in an operation to save the children and their soccer coach, who have been trapped underground for more than two weeks.