(ANSA-AFP) - PARIS, MAY 31 - France's sports minister condemned Novak Djokovic on Wednesday after he wrote a message saying Kosovo was at the "heart of Serbia" following his victory in the opening round of Roland Garros. The Belgrade-born tennis superstar scrawled "Kosovo is the heart of Serbia. Stop the violence" on a camera on Monday in Paris amid clashes between ethnic Albanians and Serbs in the territory. Kosovo, mostly populated by Muslim ethnic Albanians, broke away from the then-Yugoslavia in the late 1990s and declared independence in 2008, in a move that has never been accepted by neighbouring Christian-majority Serbia or its ally Russia. French Sports Minister Amelie Oudea-Castera told broadcaster France 2 that Djokovic's message was "not appropriate, clearly". "There's a principle of neutrality for the field of play. When you carry messages about defending human rights, messages that bring peoples together around universal values, a sportsperson is free to express them. (ANSA-AFP).