Indian rescuers trying to reach a group of miners trapped in a remote and illegal "rat-hole" coal mine are struggling to pump out water from the 370-foot-deep pit, further dimming their chances of survival more than three weeks into their ordeal.

The slow progress in the rescue efforts in the northeastern state of Meghalaya has been contrasted with the dramatic rescue of 12 Thai boys and their football coach from a flooded cave in July last year, which drew a massive international audience.

The mine became flooded after at least 15 miners went down the narrow pit on December 13. Rat-hole mines killed thousands of workers in Meghalaya before India's environmental court banned the practice in early 2014.

Many mines continued operation, despite the ban, requiring workers, often children, to descend hundreds of feet on bamboo ladders and dig coal out of narrow, horizontal seams.

"We are continuously engaged in our efforts but the terrain and conditions out here are extremely difficult," Santosh Kumar Singh, an assistant commandant with the National Disaster Response Force (NDRF), told Reuters from the site.

Navy divers and NDRF personnel had not been able to reach the trapped miners, he said.

Rescuers are now placing their hopes on a huge pump from state miner Coal India Ltd that is being installed on a concrete platform near the mine.

India's Supreme Court on Friday ordered the federal government and Meghalaya to file a report by Monday on the rescue operation. Meghalaya told the court on Thursday that nearly 86 people had been working on the rescue effort.

At its peak, the state produced coal worth $4 billion a year, or about a tenth of India's total production.

While the Thailand drama got round-the-clock international media coverage, the trapped miners in Meghalaya are getting very little attention, even within India.

"Whole media, government and us, the common people, have completely ignored them," one Twitter user, Rahul Sribastab, wrote. "The government, opposition and media have failed us."