Orlando International Airport halted flights for nearly four hours Friday — canceling dozens of flights and delaying thousands of travelers — to investigate security concerns after a camera battery that overheated and was mistaken for a gunshot.

The incident about 5 p.m. caused a panic because the popping noise from the lithium-ion battery in a camera at a security checkpoint. All flights were temporarily halted and 24 were canceled as authorities investigated, according to Phil Brown, CEO of the Greater Orlando Airport Authority.

After gates were reopened at 8:45 p.m., thousands of travelers faced longer waits to get through security and passengers who had evacuated needed to be screened again.

The panic over the situation reflected the heightened sensitivity among travelers to security issues at airports, after incidents such as bombings overseas and the fatal shootings in January in the baggage-claim area of Fort Lauderdale-Hollywood International Airport.

Mike Robinson, a traveler headed to Dallas, told the Orlando Sentinel he heard a loud pop at a security checkpoint. Because of uncertainty about the noise, Orlando police tweeted that no shots were fired and there wasn’t any danger to the public.

Robinson told the Sentinel that at least 10 bomb-sniffing dogs entered the terminal.

 “It was pandemonium,” he said of people sprinting past the security checkpoint to take cover. “Now they’re bringing people out of their gates, off-loading them to be screened again.”

Airport spokesman Rod Johnson told the Sentinel that the noise was reported shortly after 5 p.m. in front of the…