BRUSSELS/BELGRADE, Nov 21 (Reuters) - The European Union on Monday warned of "escalation and violence" after Kosovo and Serbia failed to agree in emergency talks on a solution to their long-running dispute over car licence plates used by the ethnic Serb minority in Kosovo. Kosovo has attempted this year to require its Serb minority to change their old car plates that date before 1999 when Kosovo was still part of Serbia. The dispute over licence plates has stoked tensions for almost two years between Serbia and its former breakaway province, which declared independence in 2008 and is home to a Serb minority in the north backed by Belgrade. Around 50,000 ethnic Serbs who live there refuse to recognise Pristina's authority and still consider themselves a part of Serbia. Additional reporting by Bart Meijer; Writing by John Chalmers; Editing by Josie KaoOur Standards: The Thomson Reuters Trust Principles.

---