By Sethuraman N R

NEW DELHI May 26 (Reuters) - State-run Coal India has asked its subsidiaries to ramp up coal supplies to ‌power plants to avoid shortages as the country's power demand ‌hits a record high following an intense heatwave, two sources with direct knowledge of the ​matter said.

Several regions in the country are facing power cuts, mainly at night when renewable output is not available, as record-breaking heat triggered by an El Nino weather pattern strains the grid.

As many as 21 power plants ‌have critically low coal ⁠stocks, only enough to meet less than a week's demand, according to latest data from the Central Electricity Authority, ⁠the adviser to the power ministry.

The world's largest coal miner has directed its subsidiaries to maximise dispatches using all transport modes including rail links that ​move coal ​directly from mines to power plants, ​the sources said.

Coal India said ‌on Tuesday it had urged utilities to build up stocks in advance of peak demand, particularly those located in logistically challenging areas.

India's peak power, a measure of the maximum electricity requirement, hit a record high of 270.8 gigawatts (GW) last week.

Despite 228 GW of non-fossil fuel capacity, coal still ‌accounts for more than 70% of India's ​power generation.

Coal India and its eight subsidiaries, ​which account for about 80% ​of the country's coal output, saw production decline 9.7% ‌to 56.1 million metric tons in ​April, company data showed.

The ​miner said it held 168 million tons of coal, including 47.6 million tons at power plants, enough to meet 19 days' ​consumption.

Stocks at mines stood ‌at 113.5 million tons as of May 23, up about 10% ​from a year earlier, it said.

(Reporting by Sethuraman NR; Editing ​by Nidhi Verma and Emelia Sithole-Matarise)