Ukraine’s acting president says police forces in the Luhansk and Donetsk are in disarray and institutional support for Moscow is a “colossal problem” in the east of the country.

Oleksander Turchynov’s comments come after dozens of people were killed in a fire and clashes in the Black Sea port city of Odessa as Ukraine’s bloody conflict spread from the east to the south.

He said Russian special forces were destabilising the country, but Odessa would not bend under pressure of separatism.

“The police itself which for 20 years have trained to do other things: to protect those in power, to take over people’s businesses,” said Turchynov during a television interview. “Now they are unable to take on the constitutional role of protecting the life and well-being of the people. It’s a colossal problem. Moreover, many of them are really sympathetic to separatist groups,” he added.

Moscow says Russian speakers face threats from Ukrainian nationalist militants, something Kyiv denies.

Ukraine is organising a presidential election for May 25.