Photo from UNIAN

"People are telling [Ukrainian] border guards that police patrol at a roadblock near the Russian checkpoint Novye Yurkovichi instruct travelers to use other checkpoints along the border, telling them that a combat alert has been declared in Ukraine," Slobodian told Interfax-Ukraine agency Thursday.

Read alsoRussian Duma's ex-deputy Voronenkov shot dead in Kyiv (Photos)At the same time, according to him, the State Border Service of Ukraine did not hear any official reasons from the Russian side.

Other sources inform that armed men in full gear have amassed at the Russian checkpoint.