Crimea power blackout: Russia accuses Ukraine of sabotage
Russian PM Dmitry Medvedev has accused Ukraine of "sabotage" after damage to key electricity pylons deprived Crimea of power.
He said Ukraine was "seeking objectives that are practically terrorist".
Crimea's two million people have been severely affected since the pylons were damaged on 22 November. Anti-Russian activists have been blamed.
Ukraine said Tatar activists would need to allow repairs before the power supplies could be resumed.
The loss of power to Crimea has sparked a reduction of coal supplies to Ukraine from Russia and from the pro-Russian rebel-held eastern Ukraine.
Russian forces annexed Crimea from Ukraine in March 2014.
Mr Medvedev was quoted by the Interfax news agency as saying: "The region (Crimea) has been left without electricity as a result of, in fact, energy manipulation, actions by the Ukrainian authorities.
"And legally speaking, what was done is an act of sabotage, that is to say, the destruction of industrial facilities, seeking objectives that are practically terrorist."
Speaking at a meeting with deputy prime ministers in Gorky, he said Ukraine's actions had "endangered the lives and health of many people".
Mr Medvedev said the construction of an "energy bridge" from Krasnodar to Crimea was being speeded up.
Ukraine's Energy Minister Volodymyr Demchyshyn said Ukraine would meet 20% of Crimea's power supplies once the Kakhova-Tital electricity line was repaired.
But that could only happen at a time agreed with the activists, he said, stressing that Ukraine had asked them to permit repairs.
Mr Demchyshyn said that as soon as the line was repaired, "supplies of coal will also be resumed" to Ukraine.
Only 30% of Crimea's electricity is generated locally - the rest comes from Ukraine, Russia's government daily Rossiiskaya Gazeta reported.
A state of emergency was imposed in Crimea on Sunday, and Monday was declared a non-working day.
It is still not clear how exactly the pylons were damaged in Kherson, a Ukrainian region adjacent to Crimea.
Crimean Tatar activists suggested that the pylons were blown down by the wind. But Ukraine's state energy company, Ukrenergo, said the damage was caused by "shelling or the use of explosive devices".
The activists accuse Russia of abusing Tatar rights and denying them a voice since a pro-Moscow government was installed in Crimea.
Images on social media show Ukrainian flags on some damaged pylons - and Crimean Tatar flags on others.