A search team has found a 40-metre deep shaft at Doi Pha Mee giving hope that if further drilled may lead rescue teams to Pattaya Beach where the 13 missing are believed to be taking refuge.
The team of policemen, troops and officials of the Department of National Parks, Wildlife and Plant Conservation, led by a western cave explorer, Werne Unsworth, found the shaft.
Another search team, led by the national police chief, Pol Gen Chakthip Chaichinda, also conducted search to look for shaft northward of Doi Pha Mee.
Chiang Rai governor Narongsak Osotthanakorn later said that a border policeman managed to get into the cave through the shaft which is about 40 metres deep and reported that the cave floor was muddy but not flooded.
Meanwhile, Mr Sutthisak Sornlum, chief of the soil engineering development and research centre of the Engineering Faculty of Kasetsart University, said his team had suggested possible drilling of a shaft found Thursday by a search team.
The shaft is about 1,050 metres above mean sea level or 500 metres above the cave entrance and only about 500 metres from Pattaya Beach.
But he said that to drill the shaft, a helicopter would be needed to lift a drilling machine and time consuming, so a new shaft would have to be found. But he is hopeful that drilling through a cave wall could start tomorrow.