(CHICAGO) Chicago Police rounded up 100 people in a sweep targeting gang members in the city’s most violent neighborhoods, Police Supt. Eddie Johnson announced Friday at police headquarters.

Arrests began before dawn Thursday and continued for 36 hours, nabbing 100 people on felony counts, Deputy Chief Anthony Riccio said.

The arrests were made in 15 of the city’s 22 police districts, the Chicago Sun-Times is reporting. They resulted from a six-week investigation, and Riccio said another 105 suspects are targeted for arrest in the next seven to 10 days.

Johnson has announced similar “targeted” arrest sweeps every few weeks since taking over the department earlier this year. The superintendent was joined on the podium by just Riccio and another top deputy, a break in the usual staging of his announcements, which typically see the chief flanked by a phalanx of top officers.

About 15 minutes after the press conference, the department announced more than a dozen promotions within the department’s top brass—a move that comes a day after Johnson moved to fire seven officers who allegedly tried to cover up the shooting of Laquan McDonald.