“We’ve got him,” Théo Francken, a Belgian minister,wrote on Twitter. The country’s two public broadcasters, VRT and RTBF, reported that Mr. Abdeslam had been captured and had a leg injury, and that the raid was one of four carried out in the Belgian capital.
Prime Minister Charles Michel of Belgium was scheduled to make a statement at 7 p.m. local time, or 2 p.m. Eastern Daylight Time.
The raid, carried out by a heavily armed phalanx of police officers, began about an hour after Belgian prosecutors announced that they had found Mr. Abdeslam’s fingerprint in an apartment that was raided on Tuesday.
Of the 10 men believed to have participated directly in the attacks, which were orchestrated by the Islamic State and killed 130 people, Mr. Abdeslam was the only one who was at large. The rest are dead.
Mr. Michel raced from a summit meeting of European Union and Turkish leaders about the migration crisis in Europe to deal with the situation. On Twitter, he said he was monitoring the police operations with President François Hollande of France.
“There is a link with the Paris attacks,” Mr. Hollande told reporters in Brussels, while declining to provide details of the police operation. “We need to let the Belgian police finish its work and wrap up the operation that is still ongoing.”
The raid on Tuesday was not an attempt to capture Mr. Abdeslam. The authorities had targeted the home, on the Rue du Dries in the Forest section of Brussels, as part of an effort to collect additional intelligence. Over the past four months, the French and Belgian police have raided dozens of buildings, scooped up troves of documents and questioned scores of suspects as part of their investigation.
The French and Belgian officers who conducted the raid were surprised to find the residence occupied. They immediately came under fire, and in the ensuing gunfight, a 35-year-old man named Mohamed Belkaid was killed, while two other people escaped. Four police officers were slightly wounded.
It was the second time the authorities had found Mr. Abdeslam’s fingerprints in an apartment in Brussels; in December his fingerprints werefound in an apartment in the Schaerbeek section of Brussels, along with material that might have been used to make suicide belts.
The tantalizing, and frustrating, clues suggested that Mr. Abdeslam hid in the Belgian capital after the attacks, and might be there still, although some investigators theorized that he escaped to Syria.
Belgian prosecutors said on Friday that the Algerian man killed in the raid, Mr. Belkaid, was “most probably” a man who helped the Paris attackers. Mr. Belkaid had been using fake Belgian identity papers in the name Samir Bouzid.