Polls opened in Cologne Sunday morning, a day after the knife attack against independent mayoral candidate Henriette Reker. The 58-year-old was stabbed and seriously wounded while visiting an outdoor market on the campaign trail on Saturday.

Reker's condition was described as stable following surgery for her neck wounds.

More than 810,000 citizens of Cologne are called to the polls to elect their new mayor on Sunday. According to recent surveys, Henriette Reker (standing as an independent but backed by three political parties: the Christian Democrats, the Greens and the Free Democrats) and the Social Democrat candidate Jochen Ott have the best chances in the election.

Police confirmed on Saturday that the knife attack against Reker was motivated by anger at her pro-refugee stance. Her work in the social services department of the city government included organizing accommodation for asylum seekers in Cologne. Witness statements indicated that the attacker had "xenophobic motives."

Police officials added that investigators had not ruled out mental instability on the part of the 44-year-old assailant.

The man was arrested at the crime scene and told police he was an unemployed painter and varnisher and had been living off welfare payments.

On Saturday thousands of people in Berlin turned out to a candlelit vigil in a show of solidarity against xenophobia. A similar rally was also held in Cologne.

Sunday's mayoral election was originally due to be held in September but was postponed to October after printed voting forms were declared invalid.

das/se (dpa, AFP)