The Serbian Foreign Minister, Ivica Dacic, has said a flag incident that halted a Euro 2016 qualifier against Albania was a "political provocation".
The match in Belgrade was stopped after 41 minutes when a drone carrying an Albanian flag sparked a brawl.
Uefa is opening disciplinary cases against both Serbia and Albania, AP news agency reports.
A brother of Albanian PM Edi Rama denied being detained in Serbia on suspicion of controlling the drone.
Olsi Rama told Albanian TV channel SuperSport that reports of his arrest were untrue after Serbian state TV announced he had been held on suspicion that "he masterminded and executed the incident".
He flew back to Albania after the match in the Serbian capital, which he had reportedly attended as a VIP.
Ordinary Albanian fans had been banned from attending the game between the two Balkan nations, which have a long and bitter history of rivalry.
Edi Rama is due to go to Serbia next week, the first visit by an Albanian leader to Serbia in nearly 70 years.
Play was stopped towards the end of the first half of Tuesday night's match in the Partizan Stadium when a drone appeared above the pitch, trailing a banner marked with an Albanian flag and a map of "greater Albania" showing nationalist claims on neighbouring states, including Serbia.
Serbia defender Stefan Mitrovic pulled down the flag, which several Albania players then attempted to take.
A melee involving numerous players ensued. English referee Martin Atkinson led the teams off the field after some fans invaded the pitch and clashed with members of the Albanian team.
Following a delay of about 30 minutes, the match was abandoned.
Serbia captain Branislav Ivanovic said the Albanian team was not "in a physical or psychological state to continue".
The Serbian foreign minister asked how the international community would have reacted had Serbia fans staged a similar stunt in Albania or Kosovo, the breakaway region of Serbia where the ethnic Albanian majority declared independence six years ago.
"If someone from Serbia had unveiled a flag of Greater Serbia in Tirana [capital of Albania] or Pristina [capital of Kosovo] it would already be on the agenda of the UN Security Council," he told Serbian newspaper Blic.
The Serbians and Albanians have until next Wednesday to respond to Uefa, Uefa spokesman Pedro Pinto told AP.
Uefa President Michel Platini said he was "deeply saddened" by what had happened, adding: "Football is supposed to bring people together and our game should not be mixed with politics of any kind. The scenes in Belgrade last night were inexcusable."
Fifa chief Sepp Blatter said: "Football should never be used for political messages. I strongly condemn what happened in Belgrade last night."
The prime minister's brother issued his denial after reports that he had been detained for 40 minutes before being put in a vehicle and taken to the airport.
Serbian media say he showed police a US passport after he was detained.
The Albania team returned home to a heroes' welcome in Tirana on Wednesday, AP news agency reports.
Up to 3,000 flag-waving supporters gathered outside the city's airport.
Prime Minister Rama praised the players on his Twitter page for "the pride and joy they gave".
His visit to Serbia next Wednesday became possible after the normalisation of relations last year in an agreement brokered by the EU, which both Albania and Serbia have applied to join.