A sea plane has crashed into a river killing two people on board as families gathered to celebrate Australia Day.

There were only two people on board, the pilot and a passenger, and both died at the scene in Perth, Australia.

Crowds were on the shoreline in the city in the lead up to a fireworks display and many boats were sat on the Swan River when the accident occured.

Video footage shows the fixed-wing white stunt plane circling before it nose dives into the water.

The moment the aircraft hits the river is hidden by a boat.

Onlookers said the plane was following another water plane south along the river before it banked and seemed to stall, before going down.