A man and a woman are still feared to be trapped under the debris and efforts are on to locate them, said Arora.
He added that sniffer dogs attached to the National Disaster Response Force (NDRF) were also being used in the rescue operation.
The accident occurred on August 10 at the dumping yard of state-run Mahanadi Coalfields Limited in Basundhara mining area of Kulda in Sundergarh district, 450km from Bhubaneswar.
A group of villagers were allegedly collecting coal shells from a pile of coal overburden that collapsed on them.
Overburden is the name given to the material above the coal reserve, which is removed before mining and dumped elsewhere.
Since that waste also contains low-grade coal shells, people often sneak into the prohibited mining zone area to collect these from the dumps.