Baltimore City Schools has capped attendance at board meetings and installed metal detectors and new rules on recording.

Last month, a meeting was cut short when law enforcement discovered a “perceived threat from an unknown group of individuals” in the boardroom who were “clearly communicating and demonstrating coordinated behaviors consistent with a planned activity,” the district said.

Starting at Tuesday night’s meeting, all attendees are required to pass through a weapons detection screening in the lobby, according to a news release issued by the district Monday. Participants are required to sit down, and the number of attendees is limited to the number of seats available in the room.

Only credentialed media members can use tripods or professional video and audio recording equipment, though cellphone recording is still allowed. Media members will be limited to a designated area in the boardroom, according to the release.

Meetings are every other Tuesday at 5:30 p.m. in the district’s office on North Avenue in the Barclay neighborhood in Central Baltimore north of downtown. They are also streamed and archived online.

Starting at 4:15 p.m. before a meeting, entry to the building for both the public and staff is limited to the main entrance on North Avenue except for an “accessible” entrance on Guilford Avenue, according to the release. Entry to the board meeting will start at 5 p.m., and exits will also be limited.

At the next meeting, Sept. 24, the window for public comment will start at 4:30 p.m., the district said.