A Ukrainian television station has been forced to broadcast from outside its own building after the building caught fire amid a protest.

News reports said TV Inter's headquarters in Kiev caught fire on Sunday afternoon. A group of about 20 protesters had gathered outside the building and set tires afire, the reports said.

The station is regarded by many Ukrainians as having pro-Russia sentiments. The affiliation of the protesters wasn't immediately known.

A conflict in eastern Ukraine between Russia-backed separatists and Ukrainian government troops has killed more than 9,500 people.

Kiev police official Andrei Krishenko said witnesses indicated a smoke bomb was thrown into the building, the Ukrainska Pravda website reported.

No one was reported injured in the fire. The station continued broadcasting from mobile facilities outside the building.