The fire at the National Information Systems Company building, which is producing the programs for the Inter TV channel, has sparked up due to a smoke grenade hurled by a group of unknown people, National Police Kyiv Main Directorate spokesperson Oksana Blyschyk said.

"The police received a call at about 4.30 p.m. from Shchusev Street that unknown people set the tires on fire outside the office of a television channel. Police car patrols and an investigative team from the Shevchenkovskiy police department rushed to the scene. It was found out that a group of nearly 20 people have come to the building, have placed the tourist tents and have taken the tires with them. Then they have set the tires on fire. Then they hurled it at the building, according to tentative information, a smoke grenade, and the fire has broken out," she wrote on her Facebook page on Sunday evening.

The incident was duly registered in the common police register, Blyshchyk said. Firemen, experts and a team of investigators and operatives are working at the scene.

"Several participants in the event have been taken to the police station to find out their identities and to have the explanations from them," she said.

"After the inquiry the investigators will present a legal classification to this incident," the police spokesperson said.