HALIFAX -- The navy says a destroyer that is docked in Cape Breton has been damaged and was set adrift while under tow after problems arose with repair work carried out at an Ontario dockyard.

Capt. Doug Kierstead says HMCS Athabaskan drifted for several hours off Scatarie Island on Friday after the tow line broke.

Kierstead says there is damage to the hull behind the ship's identifying numbers, though he declined to say how that damage came about.

He says the vessel was supposed to have undergone a routine refit by the end of November last year and was expected to be capable of sailing after that work was completed at Seaway Marine and Industrial Inc. in Welland, Ont.

But Kierstead says the ship couldn't steam back to Halifax on its own power due to maintenance delays and "further unforeseen maintenance."

He says the ship will remain in Sydney harbour until the hull damage has been assessed and officers determine how to safely return it to Halifax to complete the refit and repair the latest damage.