A synagogue in the Belgian city of Liège was damaged in an explosion in the early hours of Monday, police have said.

The blast happened at around 04:00 local time (03:00 GMT) in front of the synagogue and damaged windows across the street but caused no injuries, according to officers.

Willy Demeyer, the city's mayor, called the incident "an antisemitic act", while Prime Minister Bart De Wever said later on social media: "We stand in solidarity with the Jewish community."

The Belgian federal prosecutor's office, which handles terrorism and organised crime, is leading the investigation, an official said.

"An explosive device was planted or thrown - I don't know which - outside one of the synagogue's main doors," Rabbi Joshua Nejman told the AFP news agency, saying that the blast "took out the windows and the door itself".

"Fortunately" the building did not suffer further damage, the rabbi added, but that he was left shaken.

Police quickly established a security cordon around the site and the street was closed off while the investigation continued on Monday morning.

Federal prosecutors have yet to give further details about the incident.

One resident who lives close to the synagogue said the blast shook her windows.

"We immediately understood it was an explosion. But we thought it was a gas explosion," she told the public broadcaster RTBF.

"I don't think we should panic too much," one local, 76-year-old Eliane, told news agency Reuters, adding that she had lived there for many years and had never had any problems.

A number of Belgian political figures took to social media to condemn the incident, with De Wever posting on X: "Antisemitism is an attack on our values ??and our society, and we must combat it unequivocally."

"We stand in solidarity with the Jewish community in Liège and throughout the country."

Interior Minister Bernard Quintin called it a "despicable antisemitic act that directly targeted Belgium's Jewish community".

Security measures around similar sites would continue, he said, adding that security services had already been "extremely vigilant" in recent days over concerns of potential threats motivated by the renewed conflict in the Middle East.

Liège Mayor Demeyer said he was shocked by the attack and expressed support for the Jewish community, which he described as a "positive and important" presence in the city.

"We cannot allow foreign conflicts to be imported into our city," Demeyer told RTBF, in an apparent reference to the ongoing war in the Middle East triggered by US and Israeli strikes on Iran.

Three people were arrested on suspicion of plotting a drone attack on the country's prime minister in October.

The alleged plot was described by prosecutors as a "jihadist-inspired terrorist attack" on De Wever and other politicians.

Built in 1899, the Liège synagogue also serves as a museum for the history of the city's Jewish community, according to its website.

Belgium's Jewish community numbers around 42,000, most of whom live either in Brussels or Antwerp, the two largest cities, according to the Conference of European Rabbis.

A spike in reported antisemitic acts following Hamas' attack 7 October 2023 on Israel prompted Belgian authorities to step up security around Jewish sites.