The landing gear of a Delta Air Lines jet apparently caught fire during a rough landing Saturday afternoon at Atlanta's main airport, but the flight's approximately 50 passengers and crew were evacuated safely, authorities said.

Four people suffered minor injuries that did not require hospitalization, Atlanta city fire officials said. Passengers were evacuated through the rear stairs. Firefighters quickly extinguished the fire with foam spray.

There were conflicting accounts as to what caused the trouble for Delta flight 2284 from Pittsburgh, which landed at Hartsfield-Jackson Atlanta International Airport at around 4:18 p.m.

Federal Aviation Administration spokesman Kathleen Bergen said the MD-88 jet suffered either a blown tire, a locked-up brake or perhaps both, which caused a fire.

Fire officials initially said the fire was in the plane's right engine, then said it was actually in landing gear toward the back of the plane. Crews had the blaze extinguished less than a minute after they arrived, Atlanta Fire Department Capt. Jolyon Bundrige said.

Delta spokeswoman Leslie Parker said late Saturday afternoon that she did not know if there was a fire on the plane and attributed the problem to an overheated brake. She was unaware of any injuries. The passengers on the plane were transported by bus to the airport terminal.

"There was obviously smoke," Parker said. "The plane will be taken out of service and evaluated by maintenance and they'll be able to determine exactly what happened."

The damaged plane was taken off the runway and did not cause flight delays, airport spokesman John Kennedy said.