A deputy leader of the far-right party Alternative für Deutschland has apologised for falsely blaming a fatal van attack in Münster on Islamist extremists.

Beatrix von Storch said on her Facebook page on Thursday: “I made a mistake with my tweet about Münster and I’m sorry.”

She added: “Like millions of Germans I assumed that it was an Islamic attack.”

The apology comes after widespread criticism of her tweet suggesting Angela Merkel’s open-door refugee policy was to blame after a man drove into a crowd on Saturday. Two people were killed many more injured.

When authorities revealed the van driver to be a German with no known extremist links, Von Storch initially held her line, tweeting that the suspect was an “imitator of Islamist terror”.

In her Facebook post she again criticised the chancellor, saying: “I don’t ever want to be like Angela Merkel, who doesn’t admit her mistakes.”

Two people were killed and about 30 injured when a van drove into a crowd in the western German city. The driver also killed himself at the scene.

The state interior minister, Herbert Reul, criticised people on Saturday for spreading misinformation online and claiming a refugee was responsible.

AfD co-leader Alexander Gauland told foreign correspondents on Thursday that Von Storch had made a mistake with her tweet, but that he accepted her apology.

“For me the matter is resolved,” he said.