DESOTO/LANCASTER (CBSDFW.COM) – Thousands of North Texans got a rude wake-up call very early on Tuesday after outdoor warning sirens began blaring.

It started around 2:20 a.m. in DeSoto and Lancaster and residents reported to CBS 11 News they were still going off 40 minutes later.

“This is definitely not an emergency situation. It is an annoyance,” City of DeSoto spokesman Matt Smith told CBS 11.  “We are working with our emergency response officials in the region to isolate the problem.”

In Lancaster, city officials went to social media to alert residents to the problem.

The NextDoor post and tweet read, “The Emergency Outdoor Warning Sirens have malfunctioned and are automatically sounding. We are currently working to address the concern, and will provide follow-up as quickly as possible. Sorry about the inconvenience.”

Emergency dispatch centers across the region reported getting hundreds of call questioning the reason for the alarm.