New Yorkers’ morning commute was interrupted this morning by a chorus of emergency alerts, part of a manhunt for bombing suspect Ahmad Khan Rahami. The notification, delivered through an emergency system more often used for extreme weather warnings, told recipients to "see media" for a picture and call 911 if they saw Rahami — who the FBI is seeking for questioning in connection to a bombing in Chelsea this weekend.

All major American wireless carriers adopted an emergency alert system in 2012, allowing them to push SMS-like messages to all subscribers in a specific area. It’s triggered by imminent safety threats like floods or tornadoes, Amber alerts for abducted children, and alerts "issued by the president or a designee." It was used after the Boston Marathon bombings in 2013, but only to warn people of an imminent threat, not point a finger at a suspect. At this point, it’s unknown how widespread the messages were. In addition to the bombing in Chelsea, this weekend saw an explosion in Seaside Park, New Jersey, as well as the discovery of undetonated bombs in Manhattan and Elizabeth, New Jersey.

The warning was met with uneasiness by some. Carrier subscribers are automatically signed up for wireless alerts, and the message's text is accompanied by a loud buzz that’s especially jarring in spaces packed with people, where dozens of phones can go off at once. This alert was sent just before 8AM, in the middle of rush hour. And unlike with a natural disaster, it’s starting a hunt for a specific person suspected of being a terrorist — possibly one of the first times the system has been used this way.

Nothing creepier than everyone's phones going off in a crowded subway car about a wanted suspect — Loren Grush (@lorengrush) September 19, 2016

Update 9:40AM ET: Added information about Boston Marathon bombing alerts.