COPENHAGEN, Denmark -- A gunman opened fire Tuesday at a court building in Copenhagen, killing one man and seriously wounding another, authorities said.

Danish police said they arrested a suspect nearby and seized a shotgun.

The motive of the shooting wasn't immediately clear but a court spokesman called it a possible "family showdown." Police said the shooting appeared related to a court case.

Neither the suspect nor the victims were immediately identified.

Police said the incident happened shortly after 10 a.m. One victim was shot inside the Bailiff's court, which is part of the larger Copenhagen City Court, and the other was shot outside the building. Several streets around the building, which is next to City Hall, were cordoned off by police.

The Ekstra Bladet tabloid posted a photo on its website showing a police officer aiming a weapon at a person on his knees, saying it showed the suspect being arrested.

"We are likely talking about a family showdown with this tragic ending," said Soeren Axelsen, the head of the Copenhagen City Court.

He said neither of the victims was a court employee, but gave no other details.