Celtic have been fined approximately £16,700 for the “lighting of fireworks” during their recent Champions League defeat away to Borussia Dortmund.
And the Scottish Premiership champions could face a one-match ban on away fans at a Uefa club match if there is another incidence in the next two years.
Uefa said its control, ethics and disciplinary body had decided: “To fine Celtic FC €20,000 and to ban Celtic FC from selling tickets to its away supporters for a total of one (1) UEFA club competition match, for lighting of fireworks.
“Said ban from selling tickets to its away supporters is suspended for a probationary period of two (2) years, starting from the date of the present decision.”
Celtic opened their league phase with a 5-1 home win over Slovan Bratislava before losing 7-1 in Germany.