(VOVworld) – Fierce clashes between government forces and rebels erupted on Monday near a railway station at the centre of Donetsk, the stronghold of the pro-federalization protesters in eastern Ukraine that Kiev calls terrorists. Witnesses reported plumes of smoke skywards and big bangs at the contested area. Local militia blockaded streets near the city’s border while civilians anxiously fled the violence site. The government of the self-proclaimed Donetsk People's Republic has warned its citizens of avoiding contested area. Ukrainian troops equipped with tanks and armored vehicles were said to attempt to break into Donetsk.

Smoke rises over the train station on July 21, 2014 as intense shelling rocked the area, in Donetsk in eastern Ukraine. (Photo: AFP)

Vladyslav Seleznyov, spokesman for Kiev's military operations in eastern Ukraine, said Kiev’s anti-terrorist operation is going through an active phase. But he refused to comment on saying that government forces have entered Donetsk.