Russia's Energy Ministry says nearly 2 million people on the Crimean Peninsula are without electricity after two transmission towers in Ukraine were damaged by explosions.

Crimea was annexed by Russia last year but depends on Ukraine for most of its electricity supplies.

The two transmission towers in Kherson, Ukraine, were first damaged on Friday. Ukrainian activists, including Crimean Tatars, tried to block repair works on Saturday, but retreated after clashes with police.

The Interfax news agency said police official Ilya Kiva wrote on Facebook Saturday evening that the repairs had been completed, but shortly after midnight wrote a new post saying the towers had been hit by new explosions. It was not immediately clear who was responsible.

Russia's emergency services said power was being supplied to vital services on Sunday.