A German man has gone on trial charged with attempted murder over a knife attack on Cologne's new mayor while she campaigned last year.

Federal prosecutors say 44-year-old, identified only as Frank S. in line with German privacy rules, stabbed Henriette Reker in the neck on Oct. 17, trying to kill her because of her welcoming attitude toward refugees.

Reker was elected mayor the following day while in an induced coma and took office about a month later. Before the vote, she was in charge of housing refugees in Cologne. She ran as an independent with backing from Chancellor Angela Merkel's Christian Democrats and others.

The suspect could face a life sentence if convicted. Reker is expected to testify at the trial that opened Friday in Duesseldorf.