BERLIN (AP) — Germany's health minister on Wednesday partly blamed “incitement” against the government's pandemic rules on social media for the killing of a gas station clerk by a man who refused to wear a face mask.

A 49-year-old German man was arrested Sunday over the the fatal shooting a day earlier in the western town of Idar-Oberstein. Authorities said the suspect told officers he rejected the measures against the coronavirus.”

“It was a cold-blooded murder,” Health Minister Jens Spahn told reporters in Berlin, noting that the suspect had initially gone home after being refused service for failing to wear a mask, only to return later and shoot the clerk in the head.

“The question is, what is the environment, what are the circumstances in which such a crime can occur?” he asked. “This has a lot to do with the incitement, the hatred, that is posted on social media."

A Twitter account linked to the suspect followed several prominent far-right politicians, including senior members of the Alternative for Germany party. Posts from the account, which was last used in October 2019, reflect a dislike for immigrants, climate activists and the government.

Spahn said chants of “Traitors!” heard at anti-lockdown protests during the pandemic could be seen by some as legitimizing violence.

“Words eventually always become deeds,” he said.

Spahn called on Germans to speak up if friends, relatives or neighbors start spreading conspiracy theories about the pandemic.

“We must clearly and decisively say ‘no’ to any form of pandemic extremism,” he said.

Tributes were paid Wednesday to the gas station clerk, a 20-year-old student identified on condolence cards only by his first name, Alex.