BERLIN (AP) — A candidate for Chancellor Olaf Scholz’s center-left party in next month’s election for the European Parliament was beaten up and seriously injured while campaigning in an eastern city, the party said Saturday.

It was the latest in a series of incidents raising political tensions in Germany ahead of the polls. Scholz’s Social Democrats, or SPD, launched their official campaign for the June 9 vote with a rally last week in Hamburg, Scholz’s longtime home city.

Matthias Ecke, an SPD candidate, was attacked while putting up posters in Dresden on Friday evening, the party said. It said he was taken to hospital and required surgery for his injuries. Police said the 41-year-old was hit and kicked by four men and that the same group had apparently attacked a Green Party worker minutes before in the same street.

Interior Minister Nancy Faeser, who is also a Social Democrat, said that if it’s proven that the assault on Ecke was politically motivated, it would represent “a serious attack on democracy.”