MONTREAL - Five mallards have died and six other birds remain in rehabilitation following an oil spill in the St. Lawrence Seaway.

Environment Canada's Sonia Laforet says its possible more birds may be found.

The ducks and seagulls affected by the oil were brought to the Universite de Montreal's veterinary clinic in St. Hyacinthe where they were cleaned.

The surviving birds will be kept there until they're ready to be returned to the wild.

A shipping accident in the seaway on July 12 dumped some 50 tonnes of fuel into the water.

The boat involved in the accident -- the M/V Richelieu -- is expected in Quebec City on Sunday where its cargo of wheat will be unloaded in the city's port.