Four people were injured, one of them critically, after three shots were fired outside a court building in the northwestern German city of Bielefeld.

Two suspects have been arrested at the scene, according to a press release by the Bielefeld police.

A third person, whose possible connection to the shooting was unclear, was thought to be holed up in a building near the incident, but police said that was not the case. 

According to the local media reports, the targets of the shooting were relatives of a defendant in a trial that was being heard inside the court on Wednesday.

A court spokesperson said the shots were fired shortly after the end of a hearing in the trial of two men over the death of Besar Nimani, a former professional boxer. 

The German dpa news agency, citing police sources, also reported that the incident was being treated as a targeted attack on people linked to the case.

In the case, two men are accused of having fired 16 shots at Nimani, killing him as he left a barber shop on the city's high street.

The trial is taking place under tight security, with police guarding the court building and visitors, witnesses and reporters undergoing searches before entering.

Edited by: Sean M. Sinico