The rescuers included soldiers, police officers and firefighters, local news reports said.

On Sunday, military helicopters reached the volcano for the first time since the eruption, after being blocked by the thick ash in the air. Television footage showed one helicopter that had rescued three hikers, who appeared to be conscious.

The Nagano prefectural government’s emergency response center said many hikers had descended on their own, though others appeared to be trapped in shelters awaiting rescue. It said 30 of the hikers who had left the mountain were being treated for injuries, some serious. An additional 10 hikers who were injured were being treated in Gifu, according to local news reports.

The reports said at least 250 hikers could have been on the mountain when it erupted.

Nagano’s response center could not confirm local news reports that about 45 hikers were still missing on Mount Ontake. Those reports also said a dozen hikers remained stranded in shelters on the volcano’s slopes.