Serhiy Pashynsky, acting head of the Ukrainian presidential administration, said a decision has been made to block access to the town of Sloviansk, Donetsk region, with troops as part of the second stage of the operation there.

"Twenty minutes ago, Ukrainian special units began the second stage [of the anti-terrorist operation], which consists in that we have made a decision to fully blockade the city of Sloviansk to prevent help from reaching it," he told briefing in Kyiv on Friday.

The operation will continue. Its purpose is the blockade of terrorists in Sloviansk and to prevent civilian casualties," Pashynsky said.

According to earlier reports, Vasyl Krutov, the head of the Anti-Terrorist Center of the Ukrainian Security Service, said participants in the anti-terrorist operation would not storm Sloviansk because that would lead to casualties among locals.