BRUSSELS — Police and troops descended Friday on a Brussels neighborhood where a suspected bomb factory was found earlier this week, just hours after a series of raids linked to the Brussels terror attacks netted seven suspects.

Loud bangs were heard in the streets of the Schaerbeek area of the city on Friday afternoon and a bomb disposal robot could be seen inspecting a suspicious object.

One security source told NBC News that one “man was neutralized” in the operation, although it was unclear if he had been killed or merely injured.

Image: Police operation in Schaerbeek area of Brussels

Image: Police operation in Schaerbeek area of Brussels

The incident came after French officials said an operation in the northwest suburbs of Paris on Thursday thwarted a potential attack. Two sources told The Associated Press that suspect was thought to be in the same jihadist recruiting network as the ringleader of November’s massacres in the French capital.

France was among the countries which stepped up security in wake of Tuesday’s attacks, when two explosions at the airport and another on the subway killed at least 30 people and injured hundreds.

Belgian officials have kept information close to the vest while also repeatedly having to backtrack on their statements.

Thursday night’s Belgian raids focused on central Brussels, Jette and Schaerbeek — where earlier this week a separate operation found a nail-packed improvised explosive device, chemicals and an ISIS flag.

A large portion of the neighborhood was sealed off by masked police past midnight. Locals were blocked from entering their homes and swarms of armed police were on the scene.

Some eyewitnesses told The Associated Press they had heard detonations during the operation; police would not answer any questions, though, and after several hours removed a vehicle and took down the cordon after 1 a.m.

De Standaard newspaper reported on Friday that one of the people arrested was man who was seen on security footage next to Khalid El Bakraoui, the suicide attacker who detonated a bomb in the Belgian capital’s metro. The federal prosecutor’s office did not confirm the arrest and NBC News could not immediately confirm the report.

Belgian authorities have been unable to provide a final death toll or even list of nationalities for those affected by the tragedy.

Hope was fading for some families searching for loved ones. A senior U.S. official also told NBC News that two Americans had been confirmed dead in the attacks. Two New York-based siblings were also identified as among the fatalities.

Belgium raised its threat level to the highest category after Tuesday’s suicide bombings. Officials lowered it by one rung to 3 on Thursday.

Meanwhile, NBC News’ partner ZDF reported that the arrest of a 28-year-old man in Germany may be connected to the Brussels attacks. He was detained after “acting suspiciously” at Giessen train station, which is about 40 miles north of Frankfurt.

Two German security sources old ZDF that investigators discovered that three minutes before Khalid El Bakraoui blew himself up in the subway, the suspect had received a text message in French reading “fin” — which means “the end” in English. A second text message from the following day included the name “El Bakraoui.”

The suspect also had wounds on his back, for which he had been treated in a Brussels hospital on March 18, according to ZDF. That was the day police raided homes in the Molenbeek area of the Belgian capital and captured suspected Paris attacker Salah Abdeslam.

Both sources told ZDF that police were now investigating whether the man — who is of Moroccan background — may have been one of two suspects who escaped during that operation. NBC News could not immediately independently verify ZDF’s report.