BERLIN (AP) — A Syrian man has been arrested in Austria over an assault on the head of the Jewish community in Graz, the country’s second-biggest city, and is believed to have had an Islamic extremist motive, Austrian authorities said Monday.

The country’s interior minister ordered that all synagogues be guarded around the clock, the Austria Press Agency reported.

Community leader Elie Rosen on Saturday saw a man throwing stones into the courtyard of a synagogue. Police say he spoke to the man, who then attacked him with a piece of wood, initially thought to be a baseball bat. Rosen was in his car by that point and wasn’t hurt, and the assailant fled.

Interior Minister Karl Nehammer tweeted Sunday night that the suspected assailant had been arrested in Graz.

On Monday, he said the suspect is a 31-year-old refugee from Syria who has been in Austria since 2013. Police found stones in his backpack as well as a chair leg that he allegedly used as a club. Nehammer said the man admitted to the assault in questioning, APA reported.

“Investigators believe that there was an Islamist motive,” he said at a news conference. “Corresponding evidence was seized at his apartment.”

The man also is suspected of causing damage at a Catholic church and an LGBT community center, Nehammer said.

The incident has drawn widespread condemnation. Chancellor Sebastian Kurz said Saturday that he was “shaken” by the attack, pledging to do everything to bring the perpetrator to account quickly and to ensure the Jewish community’s security. The World Jewish Congress also denounced it.