Belgian riot police have clashed with hundreds of protesters at a temporary shrine honouring victims of the Brussels suicide bombings, as investigators launched fresh raids related to the attacks.
Brussels police used water cannon when scuffles broke out on Sunday in front of the Bourse, which has become a symbolic rallying point for people to pay their respects to those who died in Tuesday's attacks.
Black-clad men carrying an anti-Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group banner with an expletive on it trampled parts of the shrine, shouting Nazi slogans.
Ten were arrested and two police officers injured.
"We had 340 hooligans from different football clubs who came to Brussels and we knew for sure that they would create some trouble," Police Commissioner Christian De Coninck said.
"It was a very difficult police operation because lots of families with kids were here."
Brussels mayor Yvan Mayeur expressed his disgust, with Belgium still in mourning over the suicide bombings at Brussels airport and subway, which killed at least 31 people and injured some 270.
"The police were not deployed to protect people from these hooligans but a whole other threat," said Mayeur told RTL television.
People trying to pay their respects were also dismayed.
IN PICTURES: Tight security and tributes after the Brussels attacks
"It was important for us to be here symbolically," said Samia Orosemane, a 35-year-old comedian. But, she added: "There were lots of men who were here and doing the Nazi salute, shouting 'death to Arabs' and so we weren't able to get through."
Theophile Mouange, 52, said: "We are all here today for peace, and for the brotherhood among peoples. Not for right-wing ideas. It's neither the time nor the place."
More arrests made
On Sunday, investigators launched raids in Brussels and two other cities, taking four more people into custody.
As part of the European Union-wide hunt to nab suspects, Dutch police arrested a 32-year-old man in Rotterdam at France's request. The man is to be extradited to France.
Meanwhile, Brussels prosecutors charged another man with belonging to a terrorist group, the Belgian press agency Belga reported.
Belga named the man arrested as A Abderrahmane, who prosecutors had said on Saturday was being held for a further 24 hours after being shot during a raid in the Brussels district of Schaerbeek.
It said he was charged in connection with a related raid in France this week which authorities say foiled an apparent attack plot.
The prosecutor's office could not immediately be reached for comment.
Belgium charges three men linked to attacks in Brussels
Separately, Italian police said they had arrested an Algerian man wanted by Belgian authorities for his alleged involvement in the Belgium-based network implicated in the recent attacks in Paris and Brussels.
The attacks in Paris on November 13 left 130 people dead.
Several people have been arrested on terrorism charges in Belgium, France, Germany and Italy since the attack in Brussels.
Germany's Die Welt newspaper reported in its Sunday edition that European security authorities were searching for at least eight more suspects.
The men, mostly French and Belgian, were believed to be on the run in Syria or within Europe, the newspaper reported, citing security sources.