Some 200 French-speaking demonstrators converged on the town hall in the mainly Flemish Brussels suburb of Crainhem where they squared up against around 100 Flemish-speaking protesters.

Four councillors in the area have so far been blocked from taking up town hall seats. One, Myriam Delacroix-Rolin, was barged by protesters, with scores of police manning a barricade and making a handful of arrests, RTL television showed. No-one was seriously hurt.

The row stems from the failure to-date by the interior ministry for the regional government of Flanders, in the north of federal Belgium, to confirm councillor nominations after local elections.

Four people awaiting confirmation indicated they will complain about alleged human rights abuses across Belgium’s language divide to a United Nations rights panel in Geneva in September.

One of the four, Damien Thiery, told the rally that the leader of the Flemish nationalist N-VA movement, Bart De Wever, had to intervene.

“Mr De Wever: you suggest that Flanders can be a model 21st century society. But what are you waiting for,” he asked, quoted by Belga news agency, adding that the Flemish officials had to “quit the Middle Ages and apply the law and democratic norms.”

Belgium has not been able to name a new federal government to replace caretaker premier Yves Leterme’s administration in the year since elections delivered victory for Flemish nationalists in Flanders and French-speaking socialists in southern Wallonia.

Negotiations remain ongoing with the status and financing of bilingual Brussels, the third federal region that is home to international bodies like the EU and NATO but a city geographically surrounded by Flemish territory, a key sticking-point.