Baltimore’s 911 dispatch system was hacked by an unknown actor or actors over the weekend, prompting a temporary shutdown of automated dispatching and an investigation into the breach, Mayor Catherine Pugh’s office confirmed Tuesday.

James Bentley, a spokesman for Pugh, confirmed that the Sunday morning hack affected messaging functions within the computer-aided dispatch, or CAD, system, but said the mayor would not otherwise comment on the matter Tuesday.

Dave Fitz, an FBI spokesman, said his agency was aware of the breach and provided some technical assistance to the city.

Source: Baltimore 911 dispatch system hacked, investigation underway, officials confirm