Aizawl,  The National Green Tribunal (NGT) has registered a suo-moto case into the November 14 Mizoram stone quarry collapse incident, and asked the officials of various agencies including the Mizoram Pollution Control Board (MPCB) to appear before it on November 28, officials said on Thursday.

A total of 12 people were killed after a large portion of a stone quarry collapsed on Monday afternoon at Maudarh village in Mizoram's Hnahthial district while they were working in the stone pit.

Mizoram Pollution Control Board Member-Secretary C. Lalduhawma said that the NGT has taken up a suo-moto case and directed authorities concerned to appear before it on November 28.

"We are now preparing a report of the mishap and it would be submitted before the NGT," Lalduhawma told IANS.

The NGT has also asked the officials of the Mizoram Disaster Management and Rehabilitation Department to appear before it on November 28 along with the officials of the MPCB.

Meanwhile, the search operation was underway to retrieve the 12th and the last body.

Hnahthial district's Additional Superintendent of Police Vijoy Gurung said that hectic search operations were underway to retrieve one more body.

"It may take time to retrieve the last body. The search operation is still going to clear the rocks where the machines were buried along with the (machine) operator," the police officer said.

The State Disaster Response Force, Mizoram Armed police personnel, Border Security Force and Assam Rifles troopers, as well as volunteers of the Young Mizo Association are involved in the search and rescue operation.

Of the 12 workers, five hailed from West Bengal while three were from Assam and two each from Jharkhand and Mizoram.

Residents of Maudarh village claimed that at least five earth excavators, a stone crusher and a drilling machine were also completely buried beneath the debris.

The stone quarry, located about 160 km from state capital Aizawl, has been operational for two-and-a-half years.

A private company ABCI Infrastructures Pvt Ltd which is constructing a highway between Hnahthial and Dawn village collects stones from the quarry.