NYON, Switzerland — Russian club Zenit St. Petersburg is facing a UEFA racism charge after its fans displayed a large banner honoring convicted war criminal Ratko Mladic.

Two Serbian clubs, Red Star Belgrade and Partizan Belgrade, were also charged for similar offenses of supporting Mladic at Europa League games on Thursday.

UEFA said Friday that all three clubs faced charges of “racist behavior.” No dates were set for disciplinary hearings.

Zenit fans unfurled the banner, about 10 meters (yards) in length, during Thursday’s 2-1 Europa League group-stage win over Macedonian club Vardar Skopje.

The game took place the day after former Bosnian Serb military chief Mladic was convicted by a United Nations tribunal of genocide and other crimes in the wars following the collapse of Yugoslavia in the early 1990s.

Mladic and other Serb leaders have broad support from Russian nationalist groups, which often see them as allies.

Red Star fans drew 0-0 at BATE Borisov in Belarus, while Partizan beat Swiss club Young Boys in their Europa League games.

Partizan also faces a range of charges for incidents in Belgrade including “field invasions” and “improper conduct” by fans.