Another unexplained loud boom was heard over the Birmingham area Sunday morning, the latest in a series that has defied explanation.

Meteorologist James Spann retweeted a number of reports from people in the Birmingham area who reported hearing one or two booms around 7:30 a.m. Sunday. Reports came from Mountain Brook, Forest Park and other areas.

The Jefferson County EMA said it had gotten a report of a double boom at about 7:29, though it raised the possibility that the second boom was an echo. The agency said it had "no information on the cause at this time."

In recent weeks, the booming noise has been heard in Arab, Oxford, Anniston, Hayden, Kimberly, Center Point, Jasper, Gardendale and other areas. The National Weather Service has been unable to pin down a cause, but has said it does not appear that earthquakes are involved. Meteorites and sonic booms have been floated as possible causes.

Meanwhile, Spann's Twitter feed has become a clearinghouse for reports from people interested in the phenomenon.

We received a report at approximately 7:28 of a double boom (could have been an echo). No information on the cause at this time. — EMAJeffersonCoAL (@EMAJeffCoAL) November 26, 2017

Heard loud and clear in Mountain Brook. — Austin Whitt (@Austin_Whitt) November 26, 2017