Crowds lined the shore to wave off HMS Ark Royal on Friday
A fire broke out in the engine room of HMS Ark Royal just hours after she returned to sea following a £12m refit.
Crowds lined the water's edge at Portsmouth on Friday as the ship left for two weeks of marine and engineering tests off south-west England.
But within hours a crew member was tackling a "minor" fire in the ship's engine room.
A Royal Navy spokesman said it was put out very quickly and Ark Royal was continuing its programme unaffected.
The ship had been out of service for seven months while undergoing the work at BVT Surface Fleet in Portsmouth.
The navy spokesman added: "It was a minor fire in the engine gas turbines. These things do happen just after a refit.
"Something had overheated and the fire was put out very quickly with a fire extinguisher.
"This is why ships have trials to run in an engine and other equipment."
The ship's refit included new exhaust systems and an updated IT network.
The gearboxes, main engines and diesel generators have been refurbished and the hull has been painted with new "intersleek" paint to improve fuel consumption.
Ark Royal's commanding officer Cpt John Clink said she was now "faster, leaner and greener".
She will resume her role as the fleet flagship in the new year, taking over from sister ship HMS Illustrious.