Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

Belgium on Monday released the sole suspect prosecutors had arrested directly in relation to the Brussels terror attacks.

The stunning revelation came as Brussels honored victims of the bombings with an interfaith memorial and after a weekend of raids across Europe aimed at signalling stepped-up cooperation in wake of the carnage in the Belgian capital.

The toll from the bombings climbed to 35 early Monday. Several suspects remained in custody from Belgium to Italy and the Netherlands, picked up as part of a spree of searches carried out over the weekend. Three were charged with terror offenses though it was not explicitly clear if they were linked to any particular attack.

"The international coordination is very intense," Belgium's Foreign Office spokesman Didier Van Der Haefelt told NBC News. "You have only to look at the recent arrests."

A man who identifies himself as Faycal Cheffou speaks in a video posted on YouTube in 2014 in which he calls himself an independent journalist. YouTube via AFP - Getty Images

Only one person — Faycal Cheffou — had been charged specifically in relation to the Brussels bombings, on counts of "terrorist murder," involvement in a terror group and attempted terrorist murder.

However, in a surprise turnabout Belgium's federal prosecutor said Monday that the "Faycal C" had been released due to a lack of evidence. Further details were not immediately available.

Cheffou was arrested Thursday night outside of the federal prosecutor’s office.

Video posted in 2014 by a man who identified himself as Cheffou focused on the plight of Muslim refugees, “forgotten” by the rest of the world.

A former colleague described Cheffou as an independent journalist who "fell into" conspiracy theories.

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

"He really started being paranoid," the former colleague, Vinz Kante, told Europe 1.

Belgian media had cited police sources in saying Cheffou was the "man in the hat" seen in airport surveillance footage from just before the attacks. However, a new appeal issued by police Monday seeking help identifying that suspect appeared to cast doubt on the reports saying Cheffou was the man in question.

Early Monday, Belgium's federal prosecutor announced that three people had been charged with participation in a terror group. It did not say whether the suspects — identified only as Yassine A., Mohamed B. and Aboubaker O. — had ties to any particular plot.

Related: Belgian Police Issue New Appeal for 'Man in White'

That followed charges against two other people over the weekend, which prosecutors similarly did not explicitly link to any plot or the Brussels bombings.

Last week’s attacks put an uncomfortable spotlight on intelligence sharing between European countries, given that at least one of the bombers had ties to the Paris terror attacks.

Amidst questions over whether opportunities were missed to foil the Brussels attacks, European nations have made a show of counter-terrorism cooperation in wake of the blasts.

Italian police said Sunday they had arrested an Algerian man in Salerno over his alleged involvement in producing fake documents used by terrorists in the Paris and Brussels attacks.

A spokesman for the Brussels prosecutor identified the suspect as Djamal Eddine Ouali and said Belgium will request his extradition.

Raids were carried out in the Netherlands overnight after a 32-year-old Frenchman was arrested in Rotterdam.

French authorities requested the arrest and will be seeking the suspect’s extradition on suspicion of involvement in preparation of a terror attack.

France’s Interior Minister Bernard Cazeneuve praised the cooperation of European partners that led to arrests in France, Brussels and the Netherlands over the past several days.

One official who was less congratulatory, however, was the mayor of Brussels. He lashed out at Belgium's interior minister after right-wing protesters clashed with police and mourners in violent scenes at a memorial to the attack victims in Brussels.

On Monday evening, Brussels paused to honor the lives lost in the attacks with an interfaith memorial. The pews of the Saints-Michel-et-Gudule Cathedral were packed for the service, during which members of the emergency services carried candles to the altar.

Belgium's health minister said Monday that 96 people were still hospitalized and that the official death toll had risen to 35 after four victims died in the hospital.

That number came after Belgian officials revised the official death toll yet again late Sunday to 31. Officials initially had said the number 31 included the dead attackers but on Sunday said 31 did not in fact include the suicide bombers.

There were Belgians, Americans, Dutch, Swedes, Germans, French, Italians, Chinese and Brits among the heavy toll and three families still awaiting formal identification of their loved ones, the crisis center added.

Two more Americans were confirmed dead by the State Department late Sunday, bringing the total number of U.S. citizens slain to four. While their identities were not released, tributes have been pouring in for the two others who have been named — Justin and Stephanie Shults.