(JTA) — Three people died in a shooting inside the Jewish museum of Brussels which the city’s mayor said may have been a terrorist attack.

The shooting happened Saturday afternoon and claimed the lives of two women and one man, De Standaard daily reported. Another man was severely wounded in the shooting.

It was not immediately known whether the victims were Jewish, Charlotte Gutman, a spokesperson for the CCOJB umbrella group of Belgian French-speaking communities, told JTA.

”This is probably a terrorist attack,” Brussels Mayor Yvan Mayeur told De Standaard.

Belgian police arrested a suspect but the nature of the attack and whether it was anti-Semitic was not immediately clear, De Standaard reported.

Sources told the paper that the attack occurred at 15:50. A single shooter pulled up opposite the museum entrance, exited his vehicle with a firearm and shot four people inside. He then got back into his car and drove away.

Witnesses said they wrote down the license plate and could give a description of the man, the daily reported on its online edition.