(QHA) -

Russia suspended coal supplies to Ukraine, a move that Ukraine’s DTEK largest private energy company called unexpected and unexplained.

Ukraine has relied on Russian coal imports since the outbreak of a separatist uprising in the southeast of the country disrupted production there. Much of the coal produced in the region is sold to Russia instead which supports the rebels.

Coal-fired power plants normally provide around 40 percent of Ukraine’s electricity.

Just last month, Ukraine entered into an agreement with Russia for the future supply of natural gas which commits the former to prepay for deliveries.