London Mayor Sadiq Khan says three used water cannons bought for police under predecessor Boris Johnson have been sold for scrap, at a loss of more than 300,000 pounds ($385,000).

Johnson, while mayor, authorized police to buy the 25-year-old cannons from Germany after riots swept London and other cities in 2011.

They cost 322,000 pounds to buy and refit, but have never been used. The government banned them, citing safety risks and saying they could be counterproductive.

Khan, the Labour Party successor to Johnson, a Conservative, has been trying to sell them since he was elected in 2016.

Khan said Monday that "we have finally got rid of them." He said they had been sold for 11,025 pounds to a firm that will dismantle them and export the parts.