A synagogue in the Belgian city of Liege was damaged by an explosion early on Monday, Belgian broadcaster VRT reported, citing local police.

Belgian Interior Minister Bernard Quintin said on Monday that an explosion near a synagogue in the eastern city of Liege overnight was "a despicable antisemitic act" and that federal prosecutors were investigating, as several countries in Europe tighten security due to the US-Israel war on Iran.

"The explosion in front of the Liege synagogue was a despicable antisemitic act that directly targeted the Jewish community of Belgium," Quintin said in a post on X. "Security around similar sites will continue to be strengthened." He made no link between the blast and the Iran war.

No injuries were reported. The cause of the explosion, which happened around 4 a.m. local time (0300 GMT), was unknown, VRT said.

The explosion blew out the windows of the synagogue, as well as those of a building on the opposite side of the road, the broadcaster said.

Police cordoned off the street while a specialised counter-terrorism team investigated the incident.

Belgium, France and Germany are among a number of European countries that have said they intend to beef up security in response to the war, and have also insisted that they are playing no active role in the conflict alongside the United States and Israel.

Belgium's transport minister has demanded that security be tightened around the country's rail network.