Official sources said that over 30 miners had gone down to the 100 m pit at Nengkhol village in Nongalbibra area and accidentally punctured the wall of an abandoned mine full of highly acidic water on Friday evening.
As the water from the abandoned mine rushed into the pit, 15 miners managed to escape, the sources said.
The rest are still trapped and hopes of getting them out alive were getting dim, they said.
The district administration has engaged 10 pumps to drain the mine to rescue them, while two teams of NDRF based in Guwahati arrived at the spot late last night and launched the rescue mission today.
Three persons - the mine owner, a foreman of a clan and a head labourer - were arrested in connection with the incident and booked for causing death due to negligence, the sources said.
South Garo Hills district administration has ordered a judicial enquiry into the incident, they added.
Mineral-rich Meghalaya does not have a mining policy and coal and other minerals are being extracted by mine owners using the rat-hole method without any mechanism to ensure the safety of miners.
Villages in the coal belt in the state are virtually standing on a network of underground trenches dug to mine coal.
