China's thermal coal futures fell on Friday, reaching their worst week in 5 months, following Beijing's strongest intervention in years to increase supply and cool runaway prices of the commodity amid a widespread power crunch.

"We're now witnessing the fruits of China's supply response, as the government has given miners carte blanche to produce at full capacity - even allowing for the easing of safety inspections in some circumstances," said Atilla Widnell, managing director at Navigate Commodities in Singapore.

China has been pressuring miners to increase coal production and imports so that power stations can rebuild stockpiles before the winter heating season. However, analysts predict that shortages will persist for at least another few months.

China's state planner, the NDRC, mentioned that it was researching ways to reduce coal prices and will take all necessary actions to put them into a reasonable range, and will crack down on "excessive profits" at coal firms.

China's securities regulator has stated it will ask futures exchanges to hike fees, limit trading quotas, and crack down heavily on coal price speculation.

The NDRC "has decided that the unbridled climbing of coal prices is partially driven by those seeking to hit the jackpot by taking advantage of the power supply falling short of actual requirement," said Chinese state media outlet China Daily.