A phone alert regarding police activity on the South Side was sent in error Monday afternoon by the Chicago Office of Emergency Management and Communications.

The alert was mistakenly sent at 3:36 p.m. to phones within a one-mile radius of Guaranteed Rate Field during a routine weekly test of the system, according to OEMC spokeswoman Melissa Stratton. She said the alert was meant to be internal.

The alert read: “Test: CPD activity in your area. Remain indoors until further notice. Chicago OEMC.”

People as far as Old Town on the North Side reported receiving the message.

Another alert was sent by OEMC about 5 p.m. to correct the previous one.

The alert read: “Disregard previous alert message re: CPD activity in area. This was a test sent in error.”

Stratton said that Chicago’s dispatch centers were immediately warned that the initial alert was a test and not a bona fide event.

OEMC tweeted an apology:

“We apologize for the confusion regarding an earlier *test* alert message regarding CPD activity in the area, which was sent in error. Please disregard the message,” OEMC said in the tweet.