Ukrainian security forces have said that none of their aircraft was shot down over the town of Sloviansk of Donetsk region on Tuesday morning.

"Claims that a helicopter, an airplane or anything else was shot down have not been confirmed," Vladyslav Selezniov, "anti-terrorist operation" spokesman, told Interfax on Tuesday morning.

The latest reports suggest that one soldier was killed and around a dozen Ukrainian forces soldiers have been injured, he added.

Previously, Sloviansk militants claim they have shot down a Sukhoi Su-25 combat airplane.

"About half an hour ago we managed to bring down the Ukrainian army's Su-25. One helicopter, several tanks and one armored personnel carrier of the Ukrainian army were destroyed as well," Sloviansk "people's mayor", Vyacheslav Ponomariov, told Interfax.