Belgian authorities suspect that a fire at a Brussels synagogue on Tuesday was a result of arson, Belga news agency reported, less than four months after a deadly shooting at the city's Jewish museum.

Three people were injured by inhaling smoke from the fire, which broke out on the second floor of the synagogue in the eastern suburb of Anderlecht and was first reported at around 6:30 am (0430 GMT), Belga wrote.

Initial evidence points to arson, according to the fire services and prosecutors. The exact circumstances and reasons for the criminal act were not known, nor had the perpetrators been identified, Belga wrote.

The incident comes after a man shot dead four people at the Jewish Museum in Brussels on May 24. The sole suspect, Mehdi Nemmouche, is awaiting trial in Belgium.

The 29-year-old dual French-Algerian national is believed to have spent time fighting alongside jihadist groups in Syria. The incident compounded fears in Europe that European extremists returning from battle in Syria could mount attacks on home soil.