An armed man is holding around 20 people hostage on a bus after complaining about the 'Ukraine's system' in a series of posts online.
Police sealed off the centre of Lutsk, a city 250 miles west of Kiev, earlier today and one photograph showed officers laying on the ground using a car for shelter as they worked to rescue the victims.
The assailant is armed and carrying explosives, officers said in a Facebook statement.
Ukrainian President Volodymyr Zelenskiy said that the assailant took control of the bus at 9.25am local time (7.25am GMT).
'Gunshots have been heard, the bus is damaged,' Zelenskiy said in a Facebook statement, adding that measures are being taken to resolve the situation without casualties.
He wrote: 'Alarming news from Lutsk. In the morning, at 9:25, a citizen who informed that he had seized a bus with hostages.
'Currently, the police operation "hostage" has been introduced, and the SBU has introduced the Boomerang plan.
'It is done to make the situation settled without victims. Holding the progress of events under personal control.'
Bullet holes can be seen in the side of a white bus with blue stripes, which also had three shattered windows.
Authorities have identified the man and said that he expressed frustration with 'Ukraine's system' on his social media pages.
Ukrainian media reported that gunshots could be heard at the scene. It was not immediately clear whether anyone has been injured.
More to follow.
This article has been adapted from its original source.
