Three people were arrested for throwing firebombs at a synagogue in Sweden on Saturday, the second anti-Semitic attack in two days, authorities said.
Jewish groups condemned the attacks as "unconscionable" and demanded that authorities take action.
No one was injured in the attack late Saturday during a youth event at Goteborg synagogue and the adjacent Jewish center. Police spokesman Peter Nordengard said Sunday it is being investigated as an attempted arson.
The attack took place after some 200 people rallied late Friday in the southern city of Malmo, yelling anti-Jewish slogans and waving Palestinian flags to protest U.S. President Donald Trump's decision to recognize Jerusalem as Israel's capital.
Witness Allan Stutzinsky told the TT news agency he saw a dozen masked youths who threw what appeared to be firebombs into the garden surrounding the synagogue in Goteborg, but they failed to damage the building.
Swedish Prime Minister Stefan Lofven and other top politicians condemned the incidents and authorities increased security around the synagogue and at Jewish centers in Stockholm and Malmo.
"I'm terribly upset over the attack on a synagogue in Goteborg yesterday and calls for violence against Jews at a demonstration in Malmo," Lofven said Sunday, reports the Associated Press. "There is no place for anti-Semitism in our Swedish society. The perpetrators will be held accountable."
On Saturday, Swedish Foreign Minister Margot Wallstrom tweeted that those who called for Jews to be killed did something "totally unacceptable."
The European Jewish Congress said Sunday it was "unconscionable that Jews are under attack on the streets of Europe" and urged Swedish and other European governments to take "strong punitive action" against perpetrators.
The American Jewish Committee, meanwhile, condemned a separate protest Friday in Berlin, during which American and Israeli flags were burned in front of the U.S. embassy.
Berlin police said 10 people were detained and 12 criminal complaints were filed over the protest of Trump's decision to move the American embassy from Tel Aviv to Jerusalem.
The Associated Press contributed to this report.