The four deceased labourers are among the nine workers trapped inside the coal mine in Umrangsu on Monday after a sudden gush of water flooded the quarry.

Dima Hasao District Magistrate Simanta Kumar Das said that the process of ‘dewatering’ or draining three abandoned mines within 500 metres of the ill-fated mine helped lower the water level within it. It is possible that these mines – each with a network of narrow tunnels branching out from the wall of a vertical pit – could be interconnected.

The death toll has climbed to four after three bodies have been recovered today; five workers still remain trapped.