WASHINGTON - Several people were killed when a twin-engine private plane crashed during takeoff Sunday morning at a small airport in US state of Florida, authorities said.

The plane was taking off from Bartow Municipal Airport, about 64 kilometers east of Tampa, at around 7:15 am in a heavy fog when it crashed and caught fire, Polk County Sheriff Grady Judd said in a statement.

"For unknown reasons, but likely related to the fog, it crashed shortly after takeoff," said Judd, adding that "everyone on board perished."

The sheriff also said that they have not yet positively identified the victims, nor had an accurate number of the fatalities.

The National Transportation Safety Board and the Federal Aviation Administration will investigate the cause of the crash. Local reports said Polk County Fire Rescue is also on the scene.