The flags, which numbered in the hundreds, were deemed to be "provocative messages of an offensive nature", UEFA said in a statement.

Fans, who had been warned by the Scottish club not to display flags before the October 25th game, could be heard singing "You'll Never Walk Alone" while holding the Palestinian flags in a video shared widely on Instagram.

Supporters also unfurled two large banners at Celtic Park that read "Free Palestine" and "Victory to the Resistance".

Gaza's Hamas-run government says at least 13,300 Palestinians have been killed, including at least 5,600 children, in the war with Israel.

Celtic are fourth in Champions League Group E on one point after four games.

They were also fined £10,000 for fans blocking passageways and using pyrotechnics.