German authorities are looking into a possible political motive for a stabbing which took place ahead of local elections in the western town of Stolberg, officials said on Monday.

A 21-year-old German-Iraqi has been arrested in connection to the incident. Officials believe he stabbed a German national with a Turkish background early on Sunday, hours before polls were set to open.

The attacker allegedly opened a car door while the victim was inside the vehicle and stabbed him in the arm. He reportedly shouted "Allahu akbar" (God is greatest) during the incident.

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The 23-year-old survived but sustained "serious injuries" which required emergency surgery.

According to the authorities, the victim's father is Turkish and had previously appeared in a political ad for the far-right AfD party. The father was shown with a group of people including the local AfD leader, Hans Wolf, and a caption reading "German Turks also want change."

Wolf told the German DPA news agency that the photo was taken accidentally during a visit to a local municipality. Wolf also said people shown on the photo agreed for the image to be published online. Separately, investigators said the father of the victim told them he did not consent for the photo to be used for campaign purposes, and had no knowledge of it.

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Police said they had visited Wolf for a "preventive consultation" on his own security on Sunday.

Anti-terrorism investigators have taken over the stabbing probe, according to DPA. According to German prosecutors, the suspected attacker had already attacked someone in a similar manner in March this year.

dj/dr (AFP, dpa)