The firefighters complained of burning in their throats and eyes, MassPort spokesman Phil Orlandella said. Four were taken to a hospital as a precaution.
None of the 219 passengers or 14 crew members were hurt, according to the airline and Logan Airport.
``There was never any threat to the airplane while it was flying,'' British Airways spokesman John Lampl said. ``There was no threat to the passengers' security.''
It was unclear what caused the fire, but it had ``nothing to do with terrorism,'' Orlandella said.
The captain of the London-to-Boston Flight 239 called the Logan control tower after it landed around 9:30 p.m. Monday and said a cockpit indicator showed a fire in the avionics compartment on the underside of the plane.
Passengers ``were already de-planing when this fire happened,'' Orlandella said.
The avionics compartment has instruments that help the pilots steer and fly the aircraft, including the radio and compass, Lampl said.
It was unclear what substance caused the firefighters' injuries, Orlandella said.
