Pascal Le Segretain / Getty

Belgian police have made several arrests in connection with yesterday’s terrorist attacks in Paris.

CNN is reporting that three homes in suburban Brussels were targeted and that at least three of the attackers had lived in Belgium at some point. Germany is currently tightening its border security and has warned that extremists may be “on the run” inside the country’s borders.

In a press conference that took place shortly after 7 pm in Paris, a French prosecutor indicated that one of the attackers was a French national who had been known to police as a common criminal before he was radicalized in 2010, though French authorities did not believe he had links to terrorism. A Syrian passport was found outside the Stade de France, where two suicide attacks took place last night. The holder of that passport “passed through the Greek island of Leros on October 3,” but its authenticity is unverified. However, that hasn’t stopped many from blaming the attacks on Europe’s ongoing migrant crisis.

In the same press conference, the French prosecutor updated the death toll to 129 but warned it could go up: 352 people are injured and 99 are currently in critical condition. All seven terrorists are dead and all seven were wearing suicide belts during the attacks—the origin of the belts is currently unknown. ISIS claimed responsibility for the attacks earlier today.