BELGRADE, Serbia (AP) — Serbian officials accused Albania on Wednesday of a deliberate political provocation after a drone flew an Albanian nationalist banner over a stadium in Belgrade during a soccer match between the two Balkan rivals, sparking violence between players and fans.

The referee halted and then abandoned the scoreless European Championship qualifying match in the 41st minute Tuesday night when a Serbian player grabbed the banner — which carried a map of Albania enlarged to include chunks of its neighbors — and Albanian players tried to protect it. As the players clashed, Serbian fans then ran onto the field and clashed with Albanian players.

Serbian police announced an investigation Wednesday into who remotely piloted the drone that flew for several minutes over the stadium, while Albania’s team returned home to a heroes’ welcome for defending their nation’s honor. UEFA, the European soccer body, said it will open disciplinary cases against both Serbia and Albania over the violence at the stadium.

At the start of the match, the Albanian anthem was loudly jeered by Serbian fans and derogatory chants were heard throughout the first half. Serbian supporters also threw flares at the field.

FIFA President Sepp Blatter tweeted: “Football should never be used for political messages. I strongly condemn what happened in Belgrade last night.”

Belgrade media and officials accused Albanian prime minister’s brother, Olsi Rama, of controlling the drone from a VIP box at the Belgrade stadium — something he vehemently denied in an interview with The Associated Press.

The incident spiked political tensions between two Balkan states that have been at odds for decades, mainly over the former ethnic Albanian-dominated Serbian province of Kosovo, which declared independence in 2008. Serbia — which considers Kosovo the cradle of its statehood and religion — has never accepted Kosovo’s independence.

Albanian fans had been warned by their own soccer federation against attending Tuesday’s game in Belgrade due to the political tensions.

Serbian minister Aleksandar Vulin said the drone incident was “carefully staged” to discredit Serbia, which hopes to eventually join the 28-nation European Union, as a regional security risk.

“Had someone from Serbia flown a ‘Greater Serbia’ flag in Tirana or Pristina, it would become an issue for the U.N. Security Council,” said Serbian Foreign Minister Ivica Dacic, referring to the Albanian and Kosovo capitals.

The stadium clashes brought into question next week’s planned visit by Albanian Prime Minister Edi Rama to Belgrade, the first by an Albanian prime minister in 70 years. EU foreign affairs spokeswoman Maja Kocijancic urged the meeting to still go ahead.

“Politics should not be driven by stadium provocations,” she said.

The Albanian prime minister’s brother told the AP in Tirana that claims he remotely piloted the drone were “absurd.”

“They want to justify the situation that went beyond their control,” Olsi Rama said. “They seemed totally unprepared for an abnormal situation.”

He also said he was not detained by Serbian police, as some Belgrade media had reported, but his American passport was checked twice at the stadium during the game.

Serbian fans have a long history of violence at soccer stadiums. In October 2010, the Italy-Serbia European Championship qualifier was disrupted in Genoa by violent Serbia fans. UEFA eventually awarded Italy a 3-0 win. A massive brawl between Croatian and Serbian fans in 1990 in Zagreb, Croatia, heralded the start of the bloody breakup of the former Yugoslavia in the 1990s.

Outside the airport in Tirana, the Albanian capital, up to 3,000 flag-waving supporters cheered the team as it returned home early Wednesday. Rama, the prime minister, praised players on his Twitter page for “the pride and joy they gave us,” and said although he was abroad he was “present in my heart” at the airport reception.

Albanian Foreign Minister Ditmir Bushati tweeted that “Football should not be highjacked by extremism,” adding “Proud of our #Albania team: showed courage and maturity.”

Captain Lorik Cana, who was born in Kosovo, said the team unanimously decided not to continue with the game. He said the Albanian players felt threatened by what he called the inadequate security in Belgrade.

Albanian players “showed our neighbors we know how to respect them and also walk … with our heads high,” Cana said.

___

Semini reported from Tirana, Albania. Associated Press writer Jovana Gec contributed from Belgrade, Serbia.