Belgian police visited suicide bombers' building last month

Belgian police patrols as people gathered to mourn for the victims of the bombings at the Place de la Bourse in the center of Brussels, Belgium, Thursday, March 24, 2016. The Islamic State group has trained at least 400 fighters to target Europe in deadly waves of attacks, deploying interlocking terror cells like the ones that struck Brussels and Paris with orders to choose the time, place and method for maximum carnage. (AP Photo/Peter Dejong) (The Associated Press)

The apartment complex which was raided by police on Tuesday night after twin bomb attacks, center, is seen in Brussels, Belgium, Wednesday, March 23, 2016. Belgian state media reports that the police confirmed that two brothers Khalid en Ibrahim El Bakraoui were involved in the deadly suicide attacks on the Brussels airport and its subway system. (AP Photo/Peter Dejong) (The Associated Press)

Belgian police were called to the address used as a hideout for jihadists in Brussels a month before they took part in attacks that claimed 31 lives, the woman who phoned police that day told The Associated Press.

Although police were merely investigating fallen glass and it's unclear whether anyone was living in the apartment at the time, news that law enforcement visited a key staging post for a triple suicide bombing only weeks before it took place may add to concern over the effectiveness of the country's security forces.

Fathia Berajaa, a 41-year-old who works near the hideout, told the AP she called police on the afternoon of Feb. 8 after a pane of glass came loose from the top story window frame of the apartment building at No. 4 Max Roos Street and fell onto her Renault sedan parked below. She showed the AP her damaged car and a smartphone photo of a police officer filling out a report. The AP was independently shown a signed copy of the same document.

It's on the top floor of No. 4, in the northeast Brussels neighborhood of Schaerbeek, that police on Tuesday discovered an apparent bomb-making factory, including 15 kilograms (33 pounds) of homemade explosives and nails for use as shrapnel.

Berajaa said she called police because she wanted to discuss compensation with whoever was responsible for renovating the structure. She said two officers came and climbed to the top floor.

"They went and checked it out," Berajaa said. "They said they didn't want to come every time something like this happened."

It's uncertain how close police came to stumbling upon the plotters. It's possible the attackers, whose whereabouts during that period are unknown, had not yet arrived in the apartment.

Belgian police would not comment on the matter and prosecutors did not respond to calls.