Police have clamped down on unlicensed raves where hundreds of revellers have been congregating for Halloween.

“Several hundred people” were turned away from Harrow, north west London, on Saturday (October 29).

Officers received complaints about large groups of young people in the area, with more heading on their way to the party by public transport.

Around 150 people were found at a large industrial unit and large sound systems and nitrous oxide canisters were seized.

The Metropolitan Police said that hundreds of more people were spoken to and turned away.

A few days earlier on Monday, 23 October, a smaller event took place at an industrial unit in Haringey. Officers found around 50 people inside, with “many still arriving” but left quickly of their own accord.

Officers seized a sound systems and speakers and gave advice to the event organisers.

Ten large speakers and other sound system equipment were also seized from an unlicensed event organised in Newham in the early hours of Sunday (October 29).

Police found around 200 people at a disused office block, who were cleared from the area.

Superintendent Jack May-Robinson, responsible for policing London across Halloween and Bonfire Night, said: “Ahead of the Halloween and Bonfire Night celebrations, officers will continue to follow intelligence and lead proactive action against those that we believe to be hosting UMEs and causing anti-social behaviour.

“These events are illegal, cause huge disruption to local residents and can be dangerous environments for those attending as they are unlicensed.

“I urge anyone with any concerns to contact police so that we can interrupt these UMEs before they escalate.”