The man arrested after a Spanish tourist was stabbed at Berlin’s Holocaust memorial on Friday was a 19-year-old Syrian refugee, Berlin prosecutors said, a day before a national election in which concerns over migration are expected to boost the far-right Alternative for Germany (AfD) party.

The suspect appears to have been planning to kill Jews for several weeks — apparently motivated by the Middle Eastern conflict — which is why he chose this location, the prosecutors said in a statement.

Police arrested the suspect, whose hands and trousers were smeared with blood, shortly after the stabbing on Friday evening.

The prosecutor’s statement said the items he was found carrying in his backpack, including a prayer rug and the suspected weapon, suggested a religious motivation.

The 30-year-old Spanish tourist underwent emergency surgery after sustaining injuries to his neck and was placed in an induced coma, the statement added, adding that he was no longer in a life-threatening condition.

Campaigning for Sunday’s election has been marred by a series of high-profile attacks in which the suspects are from migrant backgrounds, shifting the focus away from Germany’s ailing economy and boosting support for the AfD. Opinion polls show the far-right party is on track to secure second place.

A stabbing in which two people were killed, including a toddler, was blamed on an Afghan immigrant, prompting the conservative CDU/CSU bloc to break a taboo on cooperating with the far-right to push a motion cracking down on migration through parliament with the AfD’s support.

In December, a Saudi man who had lived in Germany for years, and whose social media posts indicated he sympathised with the AfD, rammed a car into a Christmas market, killing six and injuring hundreds.

The Holocaust memorial, one of the German capital’s most sacred sites, commemorates the six million Jews murdered by Adolf Hitler’s Nazis during World War Two, one of the darkest episodes in human history and a continuing focus of German historical atonement.

There is, so far, no evidence linking the suspect in Friday’s stabbing to any other persons or organisations, prosecutors said.

The suspect, who arrived in Germany as an unaccompanied minor, had no prior criminal record in Berlin and was previously unknown to both the police and the judicial authorities. He is scheduled to appear before an investigating judge today for the issuance of an arrest warrant.