Osama Krayem lived a delinquent lifestyle in Rosengard, an immigrant neighborhood in the Swedish city of Malmo, before he was "brainwashed" and joined Islamic militants in Syria, community activists and his aunt said Saturday.

The 23-year-old is now under arrest in Belgium where prosecutors accuse him of involvement in the Brussels attacks.

Krayem grew up in Rosengard, a district notorious in Sweden for high crime and unemployment rates where more than 80 percent of the residents are first- or second-generation immigrants. Muhammad Khorshid, who runs a program in Rosengard to help immigrants integrate into Swedish society, told The Associated Press that Krayem comes from a Palestinian family.

"He was well-known to the local police for multiple criminal activities like thefts, for instance," said the 46-year-old Khorshid, who is from Iraq. He said Krayem "was the perfect target for radicalization — no job, no future, no money."

Malmo police didn't return calls seeking comment. Sweden's security service, SAPO, declined to comment, referring to Belgian authorities.

Krayem's aunt, Akhlass Daabas, told Sweden's TV4 that the family was stunned by his turn toward extremism.

"Suddenly he had disappeared. Nobody in the family knew about it. Then he calls from abroad and says 'I am with them and I'm not coming back,'" Daabas said.

She said "many other guys" from the area had become foreign fighters.

Krayem posted photos on social media from Syria, including one where he posed with an assault rifle in front of the black flag of the Islamic State group.

Magnus Ranstorp, a counterterrorism expert at the Swedish National Defence College, said Krayem "had also tried to recruit people from Malmo."

In 2009, Ranstorp co-authored a report warning of the spread of Islamic extremism in Rosengard.

Belgian prosecutors say Krayem was the second person present at the attack on the Maelbeek subway station in Brussels. They also say he was at a shopping mall where the luggage used in the airport attack was purchased.

"He was brainwashed but we do not know by whom, when or where," said Nabil Chibib, a 46-year-old Palestinian from Lebanon who has lived in Sweden since 1990 and said he knows Krayem's father.

Chibib said Krayem's father used to be a medical doctor and an imam in one of the area's many mosques — "not a radical one."

No one answered the door Saturday at the family's second-floor apartment. On the staircase a young man politely told the AP to leave the premises.

Chibib lamented that Rosengard, with its drab apartment blocks, often gets negative headlines in Swedish and international media. The area has long had problems with crime by Swedish standards, though it's better off than neglected and crime-ridden areas of major U.S. cities. Its most famous son is Zlatan Ibrahimovic, Sweden's most successful soccer player.

"There are two ways to get out of here — football or radicalism," Chibib said.. "Zlatan was a tough and rough kid, but he turned to football, he chose one path. He will always be one of us. Krayem not."