The violence occurred outside the presidential administration building in Kiev where several hundred demonstrators had gathered Saturday to call for arrests of top figures in an alleged military corruption scandal.
A media investigation last week detailed alleged embezzlement schemes in Ukraine’s military industry, including at a factory controlled by President Petro Poroshenko.
A police statement said the demonstrators tried to break through police lines and were setting off fireworks. Police turned them back with tear gas.
The police said one officer was hospitalized with chemical burns to his eyes.