BRUSSELS — In another blunder acknowledged after the Brussels bombings, the Belgian authorities said Monday that they had misidentified a man arrested as the missing suspect shown in an airport surveillance photo, wearing a dark hat and white coat.
The man, arrested Thursday and charged Friday, was released after three days in custody, during which some officials publicly vilified him as a terrorist. On Monday, the police said the real suspect, one of the men who took bombs hidden in luggage to a departure hall at Brussels Airport, remained at large, and they issued a new plea to the public to help identify him.
The release of the man — identified by the Belgian news media and Belgian officials as Fayçal Cheffou, who has called himself a freelance journalist — is a setback for the Belgian authorities, who have struggled for more than a year to get a handle on the growing threat of Islamic State militants.
Officials have acknowledged other serious missteps since the attacks last week, including a failure to piece together vital pieces of evidence that might have averted them.
“The evidence that had led to the arrest of the man named Fayçal C. was not substantiated by the evolution of the ongoing investigation,” Thierry Werts, a spokesman for the Belgian federal prosecutor, said in a statement. “Consequently, he has been freed by the investigative judge.”
Cheffou had been picked out of a photographic lineup by a cabdriver who shuttled three men to Brussels Airport, where two of them — later identified as Ibrahim El Bakraoui and Najim Laachraoui — blew themselves up at 7:58 a.m. Brussels time last Tuesday. El Bakraoui’s younger brother, Khalid, blew himself up at 9:11 a.m. at the Maelbeek subway station.
The death toll from the attacks rose Monday to 35, as the authorities reported that four victims who had been hospitalized died from their injuries. The toll, which was reported by the Belgian health minister, Maggie De Block, did not include the three suicide bombers.
De Block said that 96 victims were still hospitalized: 93 in Belgium, two in France, and one who was being transferred to a hospital in the United States.
Over the weekend, the authorities were said to be analyzing DNA evidence to determine whether Cheffou — who was arrested early Thursday evening in front of the federal prosecutor’s office, of all places — was the third airport attacker. But without waiting for confirmation, some Belgian officials spoke openly of Cheffou as a terrorist. On Twitter, Theo Francken, the state secretary for asylum and migration, called Cheffou “an extremist jihadi horror.”
In an interview Saturday, Yvan Mayeur, mayor of the city of Brussels, the central borough of the 19 municipalities that make up the Belgian capital, said that Cheffou had been identified in a police photo line by the taxi driver, but added that the authorities were still waiting for DNA confirmation that he was the bomber.
Mayeur added that he did not know whether Cheffou had been involved in terrorism, but did know him to be a local troublemaker who had repeatedly disrupted a camp of refugees in Park Maximilien near the Gare du Nord railway station.
Cheffou, he said, often harangued and got into fights with volunteers from Belgian nongovernmental organizations, denouncing them for not being Muslims and urging migrants in their care to rebel.
“He tried to get the refugees to turn against NGO’s because they were ‘nonbelievers,’ ” Mayeur recalled.
In September, after prosecutors declined to intervene, the mayor issued a municipal order banning Cheffou from the migrant encampment, which was later shut down.
In a video Cheffou appears to have made in July 2014, he stood in front of a detention center for refugees and asylum seekers in Steenokkerzeel, near the Brussels Airport. In the video, Cheffou faulted the government for serving Muslim refugees meals before the end of the daily fast during the month of Ramadan.
On Monday, the Belgian police again asked for help identifying the airport attacker, and they released for the first time surveillance footage showing him and the two attackers who died.
The silent footage, which appears to be slowed down, shows the three men pushing luggage carts with large black bags. The video focuses on the man in the white coat and dark hat and blurs out the rest. The man has a short black beard and appears to be wearing glasses.
Also Monday, the Belgian authorities announced that they had charged three men who were detained Sunday with participating in the activities of a terrorist group.
The men — identified only as Yassine A., Mohamed B., and Aboubaker O. — were arrested in police raids in and around Brussels. It was not clear if they were connected to the attacks last Tuesday.
The Belgian police conducted 13 home searches Sunday — four in Mechelen, a town about 20 miles north of Brussels; one in Duffel, about 25 miles north of the capital; and eight in Brussels itself — and they arrested nine people. Six were released after questioning.
The authorities across Europe have intensified counterterrorism operations in the wake of the attacks, with arrests in at least five countries, some of them connected to the attacks in Brussels and others to the Nov. 13 attacks in Paris, or other terrorist networks.
One of those arrests was made Sunday in Rotterdam, the Netherlands, where the police arrested a 32-year-old French citizen, identified as Anis B.
The French authorities believe that Anis B. is tied to Reda Kriket, a French citizen who was arrested near Paris last week on suspicion that he was in the advanced stages of planning an attack in France.