Serbian police have arrested 11 people over hate-motivated acts in France and Germany, including defacing Jewish sites and placing pig heads near mosques, authorities said on Monday, September 29.

The group of Serbian nationals were allegedly trained by another suspect, “acting under the instructions of a foreign intelligence service,” who is “currently on the run,” the Interior Ministry said in a statement, without specifying their nationality. “Their objective was also to spread ideas advocating and inciting hatred, discrimination and violence based on differences,” the statement said.

Nine heads of pigs, considered impure in Islam, were found in early September outside mosques in Paris and the surrounding region, sparking outrage and alarm over rising-anti-Muslim hatred.

In late April, the Holocaust Memorial, three synagogues and a restaurant in Paris were defaced with green paint. Three Serbs have since been charged and jailed in France as part of the investigation.

The group of 11 will be brought before the prosecutor on a range of offences, including racial discrimination and espionage. The arrests took place in Serbia’s capital, Belgrade, and in Velika Plana, a town about 100 kilometers to the south, in coordination with the security services.