Lars Erik Klason, president of Education International, a worldwide body representing teacher organisations has written to the Serbian government and is pressing for European countries to add their protests.
Mr Klason said the international community should support the efforts of the Independent Trade Union of Kosovo Teachers to keep Albanian language education going.
Since 1989 when the Belgrade government revoked Kosovo's autonomy there has been pressure to Serbianise education. Many Albanian-medium schools have been forced out of their buildings and now operate from makeshift premises. Schools have been raided by the Serbian police and teachers have been arrested and jailed. Teachers say harassment and arrests of staff and parents are on the increase.