CELTIC and Feyenoord ultras held an organised brutal brawl ahead of the Champions League fixture between their two clubs on Tuesday.

The Scottish and Dutch champions are set to face-off in their Group E opener at De Kuip in Rotterdam, Netherlands at 8pm (BST).

But it is the hooligans and ultras of each club who have already kicked off proceedings after two individual groups came to blows ahead of the game.

With fights inside stadiums now a major rarity, hooligans now look to organise meet-ups and battles in the wilderness and secret locations.

And that appears to be the case in this scenario for the ultras of Celtic and Feyenoord.

An image uploaded onto X (formerly Twitter) by an account dedicated to the football culture scene in Scotland showed seven men lined up next to each other.

It was accompanied by the caption: "Arranged fight- Celtic Active Service Unit v Feyenoord, 7x7 50 seconds (win Feyenoord)."

The men in the picture had all their faces blurred out but were wearing the same green top and appeared to be standing in a discrete rural location.

The "Active Service Unit" is taken from the same name used by the Provisional Irish Republican Army (IRA) for a military cell of four to ten members who were tasked with carrying out armed attacks.

The Glasgow outfit have a strong connection to Ireland and a unique affinity with Irish supporters, hence the connection with the IRA-influenced name for the ultras group.

Nonetheless, the social media post indicated that the group of Celtic Ultras lost their battle with the opposition.

In other posts uploaded to the social media platform, Feyenoord's ultras have also been pictured.

One image details the threats of "Celtic not welcome" which have been spray painted across the city ahead of the Scottish side's visit.

Images have also been uploaded of the ultras posing for photos with flags and banners which they have stolen from Celtic fans.

In some of the photos, however, the locals can be see holding up their own banner, which reads: "Feyenoord Zero Tolerance."

Symbols of certain movements and groups, such as the LGBTQ flag and the Star of David, can be seen beneath and have been crossed out with red lines in a sickening act.

With these organised fights kept strictly confidential, it is unknown whether there is any footage and the extent of the casualties.

A mob of Celtic fans were caught up in a street brawl with a group of Rangers hooligans earlier this year before the two sides went head-to-head in the Scottish League Cup final in February.

And last November, 40 Celtic fans were thrown off a train at Albacete for hooliganism ahead of their Champions League fixture against Real Madrid at the Santiago Bernabeu.

Feyenoord's ultras are also no strangers to hitting the headlines, having attacked a group of Union Berlin team officials ahead of a Europa Conference League game in October 2021.

That included the German club's President, Dirk Zingler, while a woman was hospitalised following the attack at a restaurant in Rotterdam.

Elsewhere across Europe, aNewcastle fan has been stabbed three times the night before the Magpies prepare to face AC Milan at the San Siro.

Brit Eddie McKay, 58, was with his son when he was viciously attacked by seven or eight knife-wielding thugs wearing balaclavas around midnight.