Belgian authorities announced Saturday that they had charged a man in connection with Tuesday's terrorist attacks, saying they believe he participated in the plot and may be "the man in white" captured in an airport surveillance video alongside the two bombers.

The man, identified by a European official as Fayçal Cheffou, appeared before a judge after he was detained Thursday night while sitting in a car in front of the Belgian prosecutor’s office.

Belgian security officials have been seeking a man captured in an airport surveillance video Tuesday, minutes before dual suicide blasts hit. The images show three men walking together, but only two are believed to have died in the blasts. The third, wearing a white jacket and a black hat -- was thought to be at-large after depositing an explosives-laden suitcase in the departures terminal. The two bombers wore black, along with black gloves on their left hands that authorities believe concealed the detonators.

A spokesman for the federal prosecutor's office, Eric Van der Sypt, said on Saturday that the man identified by his office only as Fayçal C. was being investigated as the possible third airport attacker. But he said the link "cannot be confirmed yet."

"We have to be 100 percent sure," he said. "These are very heavy charges."

Belgium’s Le Soir newspaper reported that Cheffou was the man in the video, citing an unidentified source, who said that a taxi driver who took the attackers to the airport the morning of the attack positively identified him.

Belgian media reported that Cheffou has in the past identified himself as "an independent journalist," with a history of advocacy on behalf of radical Islamist causes. He was reportedly once arrested for trying to recruit refugees in a public park, and later received an order to stay away.

The website of Flanders News posted a video that it said featured Cheffou reporting in front of an asylum center, where he tells viewers that mealtimes for detainees were not altered to account for Ramadan, when Muslims must fast during daylight hours. "This goes against human rights," he says in the video.

Two others were also charged with terrorism-related offenses, though they were not directly linked to Tuesday's attack.

In addition to Cheffou, prosecutors on Saturday said they charged a man identified as “Rabah N.” with “participating in the activities of a terrorist group,” in connection with a Thursday raid in the Paris suburbs that French leaders say foiled a separate attack on France.

A third man, identified as “Aboubakar A.,” was also arrested and charged Saturday with a terrorism-related offense. But prosecutors did not specify whether he was involved with one of the known plots.

Saturday’s announcement of the charges came a day after Belgian authorities admitted they missed a chance to press a key terrorism suspect for intelligence in the days before the suicide bombings that struck the capital, acknowledging a significant security lapse that might have allowed his allies to attack unimpeded.

Even as the men involved in Tuesday’s attacks were racing to strike, fearful that authorities were closing in on them, investigators did not ask the attackers’ jailed ally, Salah Abdeslam, about his knowledge of future plots, Belgian federal prosecutors said Friday.

The Brussels attacks left 31 people dead, while destroying a subway car and shattering the city's international airport. Airport authorities announced Saturday that they are preparing for a “partial” reopening — but not before Tuesday, exactly a week after the attackers struck.

Much of normal life in Brussels has resumed, with the metro system reopening just a day after the attacks and the streets now once again clogged with pedestrians and traffic. But there are also signs of continuing fears.

Belgian Interior Minister Jan Jambon on Saturday appealed to residents not to attend a solidarity rally that had been planned for Sunday, saying that police are too stretched by their investigation to properly secure the site of the march. Jambon did not cancel the demonstration, which has been planned for the plaza in front of the city's historic stock exchange building, the scene of a continuous vigil since Tuesday's attacks. But he "invited citizens not to have this demonstration.”

“We understand fully the emotions," he said. "We understand that everyone wants to express these feelings.”

But Brussels Mayor Yvan Mayeur said that given the number of investigations underway, the rally should be postponed. "Let us allow the security services to do their work and the march, which we too want to take part in, be delayed for several weeks," Mayeur told a press conference with Jambon at the national crisis center.

The announcement represented a striking admission by authorities that they are overwhelmed by the difficulty of piecing together information about homegrown jihadi networks that are far more extensive than previously thought.

Meanwhile, a Mariah Carey concert that was slated for Sunday was canceled late on Friday, with the singer announcing on Twitter that she had been "advised to cancel my show for the safety of my fans, my band, crew and everyone."

Abdeslam, believed to be the logistics chief of the Islamic State’s November attacks in Paris, was apprehended March 18, apparently spurring one of the Brussels attackers to write that he feared capture by the police. But after Abdeslam’s arrest, investigators concentrated solely on the Paris attacks. Abdeslam was questioned for two hours last Saturday, the day after he was captured in a raid at a Brussels safe house — and then no other discussions were held until after Tuesday’s attacks, when he refused to speak further, prosecutors said.

French newspaper Le Monde published in Saturday’s edition what it claimed to be excerpts from a transcript of prosecutors’ questioning of Abdeslam. At one point, they show him photos of the two brothers who days later would attack the Brussels airport and subway, Ibrahim and Khalid el-Bakraoui.

“I did not know them,” Abdeslam replies, according to Le Monde. The prosecutors move on, even though they had already uncovered Abdeslam's fingerprints in an apartment rented by Khalid el-Bakraoui.

The failure to push Abdeslam for concrete intelligence — even as close associates were known to be on the loose — adds to an emerging picture of intelligence agencies, police forces­ and criminal investigators that repeatedly failed to take advantage of opportunities to avert the attacks Tuesday, the worst single day of violence in Belgium since World War II.

“We cannot exclude that, if everybody had been perfect, this could have gone differently,” Belgian Justice Minister Koen Geens told a special session of Parliament convened Friday to question top security officials about the lapses.