The warning siren system in the city of Dallas was hacked on late Friday evening, causing all 156 sirens across the city to wail for up to 1.5 hour. The system was shut down manually and its current status is unknown. (more)

The incident began at about 11:42 p.m. CT on Friday when all 156 sirens across the City of Dallas were unexpectedly activated, even though a warning had not been issued. The sirens continued to wail on and off until 1:17 a.m., when the system was manually shut down.

"We can state at this time that the City’s siren system was hacked Friday night," city hall said in a statement on Saturday. "For security reasons, we cannot discuss the details of how this was done, but we do believe that the hack came from the Dallas area."

Because the warning siren system was manually shut down, authorities do not yet know whether it will operate normally once it is re-activated. "We ask residents to be patient with us in case the sirens sound again during re-activation and please do not call 911 or 311 for concerns about sirens," the statement said.

The siren activation just before midnight woke up many residents across the city and kept them up until the system was shut down 1.5 hour later. Scores of people also called 911 to seek information and Dallas became a trending topic on social media.

The City of Dallas said it has notified the Federal Communications Commission (FCC) for assistance in identifying the source of the hack. "We are putting in safeguards to ensure this type of hack does not happen again," city hall said.