Belgian police arrested three men Wednesday on suspicion of membership of a terrorist organisation as part of a probe into jihadist fighters travelling to Syria, prosecutors said.

The arrests come after six raids in the towns of Vilvoorde and Machelen, near Brussels, as part of a probe launched in 2013, the Brussels federal prosecutor's office said.

As chairman of the Annasr mosque, Mimoun Aquichouh personally knows a number of young men who left the small Belgian city of Vilvoorde to wage jihad in Syria.

They worshiped at his mosque on a quiet street in the former industrial city just north of the capital Brussels as they fought their own personal struggles before finding the path of jihad, much to Aquichouh's dismay.

Belgians living under Nazi occupation in World War II had "reasons" if they collaborated with the Germans, a nationalist politician in the country's new coalition government said Sunday.

Bart de Wever, head of the New Flemish Alliance, the largest party in the coalition, said "of course people had reasons to join with the collaboration. There were so many of them."

Belgium's right-wing coalition government won a vote of confidence just days after taking office, despite opposition demands for new prime minister Charles Michel to sack two ministers over a Nazi collaboration row. 

In a vote on Thursday evening, the government, which was sworn in on Saturday four months after a general election, received the backing of 84 deputies, with 58 voting against and one abstention.

Belgium's new right-wing coalition government was sworn in Saturday after four months of horsetrading with francophone liberal leader Charles Michel becoming the country's youngest prime minister since 1840.

For the first time a coalition of four parties -- three Dutch-speaking, including the nationalist New Flemish Alliance (N-VA), and one French-speaking -- will rule the linguistically divided country together.

Belgium's main center-right parties agreed Tuesday to form a coalition with French-speaking liberal Charles Michel as prime minister, ending a five-month period since elections without a government.

Michel -- who at 38 becomes one of Europe's youngest leaders and Belgium's youngest since 1840 -- replaces the socialist Elio di Rupo.

Belgium's parliament overwhelmingly approved plans on Friday to send six F-16 fighter jets to join the U.S.-led coalition against the Islamic State militant group.

After the vote, the Belgian government said the fighter jets had taken off for Jordan, where they could begin fighting missions over Iraq as early as Saturday.

Six Dutch F-16 fighter bombers and six Belgian ones are to join the U.S.-led air campaign against the Islamic State group in Iraq, officials said on Wednesday.

"The Netherlands will make six F-16s available for the first phase of the campaign, for one year," Dutch Deputy Prime Minister Lodewijk Asscher told reporters after an emergency cabinet meeting in The Hague.

The European Commission said Sunday it has not been told of any specific threat against it, after reports suggested its Brussels headquarters was a possible target for jihadist fighters returning from Syria.

Belgian authorities confirmed Saturday they had made several arrests as they sought to prevent jihadist fighters or sympathizers with the Islamic State extremist group from carrying out attacks.

The Belgian authorities have prevented several attacks by jihadist fighters returning home from Syria and by sympathizers with the Islamic State extremist group, a report said Saturday.

The daily L'Echo cited unnamed sources as saying the planned attacks could have been similar to the one on the Jewish Museum in central Brussels in May which left four people dead.