An army bomb disposal team has dealt with a canister apparently containing phosphorus, which washed up near Waihi Beach.

Police cordoned off a canister on a beach and called in the army yesterday because it may contain phosphorus.

The canister washed up on at Shelly Bay, Bowentown, in the Bay of Plenty shortly after 3pm on Saturday.

The New Zealand Defence Force's explosive ordnance disposal team was notified and the public who are asked to stay away from the area.

Police say an orange flash reported by locals last night was a controlled detonation, set off by the army.

Phosphorus munitions can be used for several purposes on the battlefield, including as a smoke screen, for signalling and as an incendiary weapon.