Belgian authorities have reportedly arrested a suspect in connection with the shooting at the Jewish Museum in Brussels, in which at least three people were killed.

The man has been placed in custody, according to local VTM television, and is being questioned by police.

In the aftermath of the attack, officials immediately raised anti-terror measures and increased protection for Jewish sites. The gun rampage, which happened on the eve of Belgium's nationwide election for the European parliament, was widely seen as an anti-Semitic attack.

Footage of the shooting released by authorities showed an athletic man with cap and blue shirt, carrying two bags over his shoulder and heading to the small Jewish Museum. He used a Kalashnikov to kill an Israeli couple from Tel Aviv in their 50s, and a French woman.

A government official had said a fourth victim, a Belgian man, died Sunday afternoon, but neither the interior ministry nor the prosecutor's office could officially confirm it late Sunday.

A person who was detained Saturday soon after the shooting is considered a witness and not a suspect.