Dudelange have apologised to Qarabag after a drone carrying the flag of a region disputed by Azerbaijan and Armenia caused Thursday's Europa League match to be temporarily suspended.
Play was halted in the first half of the Group A encounter in Luxembourg when a drone hovered above the pitch with the flag of the Nagorno-Karabakh region, which is derived from the Armenian flag.
Both sets of players attempted to knock the drone out of the air by kicking balls at it, with the match delayed by over 15 minutes.
Dudelange v Qarabag suspended as drone carrying Armenian flag hovers over the pitch. Qarabag players trying (and failing) to kick it down pic.twitter.com/REceYDjpr1— James Dart (@James_Dart) October 3, 2019
When the match resumed, Qarabag took control, gaining a 3-0 lead by half-time with goals from Abdellah Zoubir, Michel and Richard Almeida de Oliveira, before Dani Quintana's strike added further gloss after the interval.
Qarabag originated in Agdam, a now ghost-town in south-west Azerbaijan that was destroyed by Armenian forces in the 1990s.
Nagorno-Karabakh and some surrounding territory has been under Armenian control after a 1994 ceasefire brought a six-year war to an end. Azerbaijan and Armenia have no diplomatic relations.
Dudelange swiftly issued an apology while vowing to investigate the incident.
"We apologise to [our] guests from Azerbaijan," the club tweeted. "We have nothing to do with this provocation. We'll figure [it] out!"
It is not the first time tensions between the neighbouring nations of Azerbaijan and Armenia have caused controversy in the Europa League.
Armenia star Henrikh Mkhitaryan elected not to travel to Baku for the 2018-19 final against Chelsea in May, having also sat out a 3-0 away win over Qarabag in last season's group stage.
Qarabag's 4-1 victory takes them level on points with their hosts with one win apiece, with La Liga outfit Sevilla's perfect start seeing them top the group comfortably.
Dudelange have been struggling domestically, with just two wins and seven points from their opening seven league games in Luxembourg's top flight putting them eighth out of 14 teams, 11 points off the league leaders.
Qarabag, meanwhile, have won all of their first six league games to go eight points clear at the top of the Azerbaijan Premier League, conceding just one goal so far.