China's government has allowed some northern cities to burn coal in a temporary policy U-turn, as the country faces a heating crisis.
Beijing had banned the use of coal for heating this winter in an ambitious plan to reduce pollution.
Recent winters had seen heavy smog blanket China's northern region.
But millions are reportedly now left without proper heating, after failing to switch from coal to other fuels in time for winter.
The coal ban has also reportedly led to a gas shortage as people rushed to switch to the alternative source, which has compounded the problem.