Utrecht police say they have now arrested two men on suspicion of setting fire to a man in an electric wheelchair on Tuesday.

The 69-year-old victim was set on fire in his chair on the Smaragdplein in the south of the city at around 3.30pm. Bystanders were able to pull the man out of the chair and call for an ambulance. He was later taken to a specialist burns unit, where his condition is said to be serious.

One of the two men arrested was picked up on Tuesday evening on the basis of witness statements and surveillance camera footage. He is 37 and comes from Utrecht. The second man, who is 55, was arrested on Wednesday morning.

Police say they suspect the men knew each other, and city mayor Sharon Dijksma said on Tuesday that they may have been in conflict.

She described the attack on the wheelchair-bound man as a gruesome act of violence. “The impact is so much greater because the victim could not get away,” she said.