Kosovo tennis federation accuses Serbian tennis champion Novak Djokovic that he exacerbated an already tense situation after the world No. 3 wrote that Kosovo is “the heart of Serbia” on television after winning the first round at the French Open.

Around 30 NATO peacekeepers were injured on Monday (29/5) in clashes with Serb protesters in the northern Kosovo town of Zvetsan, where Djokovic’s father was born and raised. Serbs, who make up the majority in the north of Kosovo, have never accepted the country’s 2008 declaration of independence from Serbia.

“Kosovo is the heart of Serbia. Stop the violence,” 22-time Grand Slam winner Djokovic wrote in Serbian to a television camera at the French Open in Paris. He later explained that he was against the war, but defended his statement and described the Kosovo situation as a “precedent”:

“As the son of a man born in Kosovo, I feel the need to give my support to our people and to all of Serbia,” he told reporters. “My position is clear: I am against wars, violence and any kind of conflict, as I have always said publicly. I sympathize with all people, but the situation with Kosovo is a precedent in international law.” he said.

The president of the Kosovo Tennis Federation, Jeton Hadergionai, said: “Novak Djokovic’s comments at the end of his Roland Garros match against Aleksandar Kovacevic, his post-match press conference and Instagram post are deplorable.”

Hadergionai accused Djokovic of using his status as a well-known personality to stir up tensions: “Novak Djokovic has already been the protagonist of similar actions in the past.

Despite the general anti-violence message, the statement “Kosovo is the heart of Serbia” and other post-match statements made by such a public figure, on the occasion of a global event like the French Open, directly lead to the raising of the level of the tension between the two states, Serbia and Kosovo,” the statement added.

The French Tennis Federation (FFT), which organizes the French Open, told Reuters that “there are no official Grand Slam rules about what players can or cannot say. FFT will not make any statement or take a position on this matter.”