Liverpool supporters were reportedly attacked by up to 20 hooligans, who acted "like a pack of dogs", in Kiev on Thursday night.
Thousands of Liverpool fans are currently in Ukraine ahead of the Champions League final against reigning European champions Real Madrid on Saturday night.
The attack is understood to have taken place just after 8.30pm local time, with locals wearing hoods and bandanas descending on the Rooster restaurant in the shadow of Kiev's Olympic Stadium.
"We were having dinner, completely minding our own business. I didn't come here for this. I came to watch the football," The Mirror quotes Jason Frost, 50, from Nuneaton as saying.
"We've been here for four hours and then we're getting attacked. They came at us like a pack of dogs. It just kept coming. It was terrifying."
Ukrainian police were reportedly on the scene quickly.