BERLIN (AP) — Thousands have gathered in cities across Germany to hold vigils for the victims of a racially motivated shooting, amid growing calls for authorities to crack down on far-right extremism.

A 43-year-old German man shot dead nine people of immigrant background in the Frankfurt suburb of Hanau Wednesday before killing his mother and himself. The man, identified as Tobias Rathjen, left a number of rambling texts and videos espousing racist views and claiming to have been under surveillance since birth.

The attack came amid mounting concern about far-right extremism reflected in earlier attacks and the rise of the anti-migrant party Alternative for Germany, or AfD.

A top official in the center-left Social Democrats, a junior partner in Chancellor Angela Merkel's governing coalition, accused AfD of providing ideological fodder to people like the Hanau shooter.

“One person carried out the shooting in Hanau, that's what it looks like, but there were many that supplied him with ammunition and AfD definitely belongs to them,” Lars Klingbeil told public broadcaster ARD on Friday.

Parts of AfD are already under close scrutiny from Germany's domestic intelligence agency. The party has rejected all responsibility for far-right attacks, including the anti-Semitic attack on a synagogue and the killing of a regional politician last year.