Around 30 people interrupted a conference at Zurich University late Friday to protest against Hungarian Minister for Human Resources, Zoltan Balog, local police told the Swiss news agency ATS.

Police intervened when the demonstrators began throwing eggs at the conservative minister, who was giving a lecture entitled “Hungary’s Roma — a problem or an opportunity?”

The group that called for the demonstration told ATS that the minister had “shown moderation” in his talk, but stressed that his agenda was characterised by “the singular culture of a police state.”

Activists say that Hungary’s Roma population, the country’s largest but poorest minority, faces open discrimination with anti-Roma rhetoric and violence on the rise.

A fight broke out when police attempted to bring the situation under control, and a police officer was slightly injured, ATS reported.

One person had been arrested for violence and threatening an officer, but had been released following questioning, according to police, who did not immediately respond to AFP’s request for comment.