Residents in Bel Aire and north Wichita received a rude awakening early Thursday morning when a tornado siren began blaring — and kept it up for more than half an hour.

Several people called 911 at around 2:30 a.m. Thursday to report tornado sirens were going off “all across north Wichita,” Sedgwick County Emergency Management director Randy Duncan said in an e-mail response to questions.

A check of the warning device system determined only one siren, located at 5033 Lake Breeze Court in Bel Aire, was sounding, Duncan said. That siren was shut off by a repair vendor at 3:13 a.m. — meaning it sounded for about 45 minutes.

The malfunction appears to be the result of “an internal issue” with the siren, county spokeswoman Jill Tinsley said in an e-mail reply to questions. Until the problem is diagnosed and repaired, she said, that siren will remain out of service.

The outdoor warning devices are only intended to alert people who are outside, authorities said.