The call to prayer on a phone caused the plane to make an emergency landing

A Southwest Airlines flight from Tennessee to Florida was forced to make an emergency landing at Atlanta Airport in the US after a passenger's phone blared out the call to prayer. 
During the flight, a timer on a passenger's phone that reminded them of the prayer time started and the call to prayer sounded. The crew took it as a security threat and notified the dispatcher, and the plane made an emergency landing. Then, special forces boarded the plane, detained the passenger, and conducted a search.
After the search, no danger was detected, and the passenger was released. The airline called the incident a "misunderstanding" and apologized to passengers for the delay.