Serbia's foreign minister said Wednesday an incident in which a pro-Albanian flag flown by drone sparked violence on and off the pitch at a Serbia-Albania football match was a "political provocation".
The Euro 2016 qualifying tie between the Balkan rivals had to be abandoned on Tuesday after the drone carrying a "Greater Albania" flag flew low over the Partizan Stadium in Belgrade.
The banner was pulled down by Serbian player Stefan Mitrovic, triggering a brawl between the two teams.
FIFA boss Sepp Blatter said football "should never be used for political messages", while the head of European governing body UEFA, Michel Platini, said the incident was "inexcusable".
The match descended into chaos as a handful of the 20,000 Serbian spectators ran on to the pitch and tried to assault the Albanian players.
English referee Martin Atkinson ordered the teams off the pitch as smoke bombs and other missiles rained down from the stands.
Albanian fans had been banned from attending the match.
The European Commission said it was "disappointed" by the violence and praised Belgrade's "professionalism" in dealing with the situation.
The incident threatens to hamper next Wednesday's visit to Serbia of Albanian Prime Minister Edi Rama, the first of its kind in 68 years.
Serbian Foreign Minister Ivica Dacic said the drone incident was a pre-planned "provocation" and blamed Rama's brother Olsi Rama for orchestrating the stunt. He denied the claims.
"What is particularly disturbing is that it is the work of the brother of the Albanian prime minister, who is about to be hosted by Belgrade," Dacic said.
The planned visit was made possible after relations between the two countries were normalised by an EU-brokered agreement in April 2013.
Albanian officials were unable to comment on whether the prime minister intended to go ahead with the Serbia trip.
"The goal of Rama's visit to Belgrade is completely different from what has happened" during the match, deputy prime minister Niko Peleshi said.
Serbia's interior ministry said Rama's brother was arrested over the incident and claimed he had controlled the drone from his seat in the stadium's executive box.
But Olsi Rama, who later returned to Tirana with the Albanian team to a hero's welcome from thousands of fans, said he had "nothing to do with the drone."
"I don't understand where this story came from," Rama said.
"I was neither arrested nor detained," he said, saying that he had merely been asked by Serbian police to show his US passport and his camera.
'Major international scandal'
Relations between Tirana and Belgrade have been strained over the issue of the mainly ethnic Albanian former Serbian province of Kosovo and the Albanian minority in southern Serbia, who frequently demand more autonomy.
In Belgrade, some see Tirana's interest as part of a plan to create a "Greater Albania" uniting Albanian communities in Albania, Kosovo, Montenegro, Macedonia and southern Serbia.
Kosovo's independence, proclaimed in 2008, has been recognised by more than 100 countries, including the United States and most EU states.
"The intensity of the hatred of both young Albanians and young Serbs (at the match) is amazing -- it is, of course, a major political and international scandal," political analyst Dusan Janjic told AFP.
The only appropriate response was to ensure the rapprochement between Belgrade and Pristina was not halted, he said.
The premature end to the match was greeted with joy by 5,000 Kosovar Albanians who gathered to watch on TV in Kosovo's capital Pristina, shouting "Greater Albania" and "victory".
Ethnic Albanians also celebrated in Macedonia, honking car horns.
On Wednesday, hundreds of high-school students marched through Pristina chanting "Greater Albania".
Serbia's captain, Chelsea defender Branislav Ivanovic, said he was dismayed by the events at the match.
"In the name of my team I can say that we wanted to continue the match... but the Albanian players said they weren't in the physical or psychological state to continue," he said.
Kosovo's formation was made possible by a bloody chain of events after the end of the Soviet era.
The demise of the Soviet Union in 1990-91 created the conditions for the bloody wars that broke Yugoslavia apart into six multi-ethnic states, including Serbia.
NATO carried out a 78-day bombing campaign which led to Serb troops pulling out of Kosovo in 1999 and brought an end to the Serbian government's repression of the ethnic Albanian population.