BRUSSELS — Belgian riot police clashed Sunday with hundreds of right-wing protesters at a temporary shrine honoring victims of the Brussels suicide bombings, as investigators launched fresh antiterror raids, taking four more people into custody.
Police used water cannons when scuffles broke out 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 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.’’
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,’’ Mayeur told RTL television.
People trying to pay their respects were also dismayed.
‘‘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,’’ said Theophile Mouange, 52.
In a separate development, a second American victim of the Brussels attack was identified. Stephanie Shults had not been seen since Tuesday. Her employer, Mars Inc., said in a Facebook post that her family had confirmed that she and her husband died in the bombings at the airport. Justin Shults’s death was confirmed Saturday.
Justin Shults was originally from Gatlinburg, Tenn., and his wife is a Lexington, Ky., native.
Italian police in the southern city of Salerno said Sunday that they had arrested an Algerian wanted in Belgium for an alleged false ID crime ring.
Djamal Eddine Ouali was arrested Saturday in the town of Bellizzi, said Luigi Amato, the head of Salerno police’s antterrorism squad. Ouali, 40, was being held pending extradition.
Belgian prosecutors said the man is thought to have made false documents for some of the attackers in the Nov. 13 massacre in Paris, including top suspect Salah Abdeslam. Investigators are trying to establish whether the same false ID ring provided papers for the March 22 attackers.
Prosecutors said Sunday morning’s raids in Belgium were linked to a ‘‘federal case regarding terrorism’’ but did not specify whether it had any links to the March 22 attacks.
Thirteen raids were conducted in the capital and the cities of Mechelen and Duffel on Sunday. An investigating judge is to decide later whether to keep the four in custody. Five were released after questioning.
Suspected plotters also were arrested Sunday in Italy and the Netherlands, though few details of their activity were released immediately.
Belgium’s interior minister, Jan Jambon, conceded Sunday that decades of neglect had hampered the government’s response to extremism. He said the government has invested $670 million into police and security services over the past two years but that Belgium’s system is still lagging.
As international pressure on Belgium has mounted for serving as an unwitting rear-base for extremist fighters who launched the Nov. 13 massacres that left 130 dead in Paris, the government has felt forced to defend its choices and the actions of investigators. Lawmakers are demanding an inquiry.