GHENT, Belgium (AP) — Four armed men have entered an apartment in the western Belgian city of Ghent, and police have blocked off a wide perimeter around the area.

Police said Monday that a few hours after the men entered the apartment it was still unclear whether they had taken any hostages.

At first sight, it didn't appear to be an act of terror, said federal police spokeswoman Annemie Serlippens. "There appears to be nothing political. And it does not seem to be going that way."

By midmorning a big police operation had been set up in the working-class neighborhood to keep bystanders away from the scene.

Media reported there already had been a hostage incident in Ghent linked to extortion two months ago.