Waste crews say they collected around 13 tonnes of laughing gas canisters from the streets following the Notting Hill Carnival.

Nitrous Oxide canisters must be collected separately to other waste as there is a risk they could explode if compacted.

Kensington and Chelsea Council says around five skips full were collected which is around 12,000 canisters.

The authority says this slowed down the clean up operation, which is already one of the biggest street clean ups in Europe.