Brussels prosecutors said Sunday police had carried out 13 new raids in various districts in and around the Belgian capital as part of investigations following last weeks' bomb attacks.

In a statement, the federal prosecutor's office said a total of nine people were questioned "in the context of a terrorism file." Five were later released. The agency said it could not give further details.

Europe’s security agencies are hunting for at least eight suspects believed to have assisted with the Islamist attacks in Paris and Brussels, Die Welt am Sonntag newspaper in Germany reported.

Citing security sources, the paper said the suspects, most of whom are French and Belgium citizens, are believed to be either in Syria or on the run in Europe.

Die Welt said the suspects had been in contact with Abdelhamid Abaaoud, the presumed ringleader of the Paris attacks who was killed by French police in a shootout Nov. 18, and Salah Abdeslam, the prime surviving suspect of the Paris attacks, who was captured in Brussels earlier this month.

Germany’s Federal Criminal Police Office (BKA) is involved in the manhunt, Die Welt said. The BKA declined to comment.

Meanwhile, police used water cannon to control hundreds of protesters in central Brussels on Sunday after they ignored an official call for solidarity marches following Tuesday's bomb attacks to be postponed.

White-helmeted riot police moved behind the water cannon to push back the crowd, which public broadcaster RTBF said numbered between 500 and 1,000.

Earlier, Italian police arrested an Algerian suspected of making documents for militants linked to the Brussels bombings, and Belgian authorities charged a man connected with a French raid as the investigation into the attacks spread to other countries.

With links to the Paris attacks in November becoming clearer, and amid criticism that European countries have not done enough to share intelligence on suspected Islamist militants, cooperation appeared to be deepening.

The suicide bomb attacks targeting Brussels airport and a rush-hour metro train on Tuesday killed 31 people, including three of the attackers, and wounded hundreds more. The Islamic State group has claimed responsibility.

The Belgian press agency Belga said Sunday that prosecutors charged the man in connection with a raid in Paris on Thursday that authorities say foiled an attack plot in France.

Belga named him as Abderamane A.; prosecutors had said Saturday that he was being held after being shot during a raid in the Brussels district of Schaerbeek. The prosecutor's office could not immediately be reached for comment.

In southern Italy, Algerian Djamal Eddine Ouali, 40, was arrested by DIGOS antiterrorism police after a series of raids and arrests in Belgium and Germany, Italian media said Saturday.

Ouali was suspected of having made false documents for militants connected to the attacks, Sky TG 24 television and other media said. His name was found in documents in a raid in an apartment near Brussels last October, including some with photos of militants involved in the attacks in Paris and in Brussels and the aliases they used.

Belgian prosecutors also charged three men on Saturday, including Faycal C., whom Belgian media identified as Faycal Cheffou and said he was "the man in the hat", as he has become known, in last Tuesday's airport CCTV footage that showed three men pushing baggage trolleys bearing luggage at the airport.

However, investigators have still not fully confirmed that Cheffou is that man, a person close to the investigation told Reuters.

The two others in the picture are believed to have blown themselves up.

Cheffou was charged with taking part in the activities of a terrorist group, and actual and attempted terrorist murder.

The other two charged on Saturday, Aboubakar A. and Rabah N., were accused of terrorist activities and membership of a terrorist group. Rabah N. was also wanted in connection with the raid in France.

Brussels Mayor Yvan Mayeur told Le Soir newspaper that Cheffou had been detained a number of times at a park where he sought to encourage asylum seekers to turn to militancy.

As the web of links between the suspects and attacks emerges, German lawmakers said Europe urgently needed to improve the way its security agencies share information.

Organizers called off Sunday's Belgian solidarity march after officials, including the mayor, urged people to stay away in order to spare the overtaxed police force amid fears of another attack.

A video posted on social media outlets used by Islamic State on Saturday showed a Belgian militant in the group's de facto capital Raqqa, Syria, taunting his home country in Flemish.

"You learned nothing from the lessons of Paris, because you continued fighting Islam and the Muslims. For this I want to tell you that the attack in Brussels is reaping what you had sown with your own hands," said Hicham Chaib, whose nom de guerre was given as Abu Hanifa al-Beljiki.

"Just as you bomb the Muslims with your F-16s, we will fight your people."

The authenticity of the video could not immediately be verified by Reuters.

Officials said 24 victims of nine nationalities had been identified so far from the attacks in Brussels, where the European Union and NATO are headquartered. Fourteen were identified at the airport and 10 on the metro. A further four people remain unidentified.

In addition, 340 people were wounded, according to the latest official toll on Saturday, of whom 101 are still in hospital, 62 of them in intensive care, many with severe burns.

With the march canceled and many celebrating the Easter holiday, the streets of the jittery capital were quiet on Sunday.

"It's obvious we cannot celebrate Easter as we usually do," Monsignor Jozef De Kesel, archbishop of Brussels, told Reuters at the central cathedral.

"The foundations of our society, freedom, respect for others, have been hit, attacked."