Celtic's match against Dundee FC in the Scottish Premier League was interrupted when visiting fans threw tennis balls and oranges onto the pitch after the kick-off in protest against the club's management, reports the AP agency, BTA reported.
Footballers and staff from both teams helped remove the thrown objects before the match at "Dennis Park" to be renewed, with defending champions Celtic losing 0-2 away.
It was Celtic's first defeat against Dundee since 1988 and left the team five points behind leaders Hearts.
Away fans chanted against Celtic chief executive Michael Nicholson and chairman Peter Lowell, with one banner reading "Fired by the board".
Fans are angry at the club's early exit from the Champions League and what they describe as an "archaic transfer strategy".
The Celtic Fans Collective has launched a campaign called "Not a penny more", calling on fans to boycott club merchandise, stadium tours and club events, as well as to refuse to buy food or drink at the stadium "Celtic Park". The campaign is expected to be reviewed in February.