SLAVYANSK (Donetsk Region), May 11 /ITAR-TASS/. A security checkpoint of Ukrainian federalization supporters near the city of Slavyansk in east Ukraine’s Donetsk Region is being shelled from 120-millimeter mortars by law enforcers loyal to Kiev, an Itar-Tass correspondent reported from the scene on Sunday.

Militia representatives say Kiev troops may start a storm after the shelling, which is accompanied by frequent sounds of explosions. There are no data on victims yet. The militia security checkpoint is situated in the vicinity of the village of Andreyevka near a TV tower. Problems with communications have already started. The checkpoint under fire is at a railroad crossing, where militiamen mounted a few freight cars blocking the road to the city.

Massive protests against the new Ukrainian authorities, who were brought to power in Kiev amid riots during a coup in Ukraine in February, erupted in Ukraine’s Russian-speaking southeastern territories after the secession of the Crimean Peninsula, which declared independence on March 11 and joined Russia on March 18 following a referendum.

Southeastern Ukrainian protesters demand broader powers for their regions. Some demonstrators have seized government buildings.

The Kiev authorities have been conducting what they call an antiterrorism operation in eastern Ukraine. Russia, which does not recognize the de facto Ukrainian leaders, has condemned the operation, apparently aimed to crack down on Ukrainian federalization supporters.

Dozens of people have died in the past days in clashes and a fire in the southern city of Odessa after radicals set ablaze the Trade Unions House and in the southeastern city of Mariupol when Ukrainian law enforcers opened fire from armored vehicles on participants of a rally held in honor of Victory Day.

The eastern Ukrainian Donetsk and Lugansk regions will hold referendums on self-determination on Sunday.