The “NOLA Ready” emergency alert Twitter account for New Orleans, most often associated with hurricane preparedness, posted five messages, warning of “suspicious activity” on city networks and informing residents that the city had “activated its Emergency Operations Center.”

One of the tweets said the city is working with “cybersecurity resources” from the FBI, Secret Service and National Guard. The city said emergency services such as 911 and the fire department were still running, and didn’t specify any agencies that had been shut down.