Hari Lal Chouhan, Superintendent of Police in Godda, where the mine is located, said seven bodies have been pulled out of the debris so far. The exact number of those feared trapped is unknown.
He added that as many as 20 vehicles have been buried in the landslide.
The cause of the landslide is still being investigated.
Catastrophe struck the vast mine Thursday evening local time, but rescue teams were unable to start their operation straight away due to a lack of technology, according to police officials.
Mining operations were reportedly taking place 200 feet beneath the ground.
Mr. Chouhan confirmed that a National Disaster Response Force (NDRF) team were now traveling to the site to help dig through the mud.
Prime Minister Narendra Modi responded on social media.
The mine is in Jharkhand, one of the major coal-producing states in India, and run by state-owned Eastern Coalfields Limited.
India is one of the world’s top three coal consumers and is expected to surpass the United States in terms of coal consumption by 2030.