New Delhi, India: The death toll from a mine collapse in eastern India’s Jharkhand state rose to 16 on Sunday as rescue workers continued to search for the bodies of seven missing miners.

A massive mound of earth caved in late Thursday at Lalmatia open cast mine, around 240 miles (390 kilometres) from the state capital Ranchi.

‘We have now already taken out 16 bodies and think the toll may go up to 23,’ Jharkhand police spokesman RK Mallick told AFP by phone.

‘Besides the challenging terrain and foggy weather, the cave-in area is spread around 300 metres and it’s obviously taking time to clear the debris and search for the unaccounted miners,’ he added. 

Baleshwar Mahato, a bulldozer operator at the mining site whose son died during the incident, said the mine’s operators ignored two safety warnings prior to the collapse.

‘After that first warning, there was another alert at about 6:00pm (on Thursday), when a bigger chunk of mud slid down,’ Baleshwar told The Indian Express.

‘But work continued where Kuleshwar (his son) was and then, this tragedy struck,’ he added.

There was no immediate explanation for the collapse, but the government has launched an investigation into the incident.

Jharkhand is one of the richest mineral zones in India, accounting for around 29 per cent of the country’s coal deposits. However it is also one of India’s poorest areas and the epicentre of a Maoist insurgency.

India has maintained a relatively safe record in mining-related accidents compared to neighbour China, which on average reports around 1,000 fatalities every year.

In 2015, India recorded 38 deaths across 570 mining sites.

The last major mining accident in India occurred in 1975, when 372 workers were killed following the flooding of Chasnala mine in Dhanbad.