Another 15 drunken fans were not allowed into the stadium for the game Saturday evening, Sofia police chief Valery Yordanov told a press conference Sunday.

One 25-year-old CSKA fan was taken to hospital with serious injuries to the head and face, hospital sources added.

CSKA won the game 3-1 at Levski's home ground but only after 3,000 away fans were evicted from the stadium at halftime following an injury sustained by a policeman.

Riot police, some on horseback and manning water cannons, were used to disperse the angry crowd in the ensuing clashes with police outside the stadium that saw several buses damaged and many shop and car windows smashed.

Yordanov said that more arrests of fans for hooliganism were to follow as police reviewed CCTV recordings of the clashes.

Some 1,455 policemen were deployed in and around the stadium after the football union refused an earlier kickoff or switch of venue for the game.

Levski and CSKA are Bulgaria's most popular teams and traditional arch-rivals and their matches are often marred by fan violence.

Levski are currently second in the Bulgarian league standings with 32 points from 16 matches. CSKA are fifth with 29.