Overcrowding fears lead to closure of event playing host to some of biggest names in electronic music

Fears about overcrowding led to the shutdown one of the UK's largest electronic music festivals on Friday night amid chaotic scenes and the arrival of police to help facilitate the evacuation of thousands of people from the venue in London's docklands.

Irate members of the public lambasted Bloc 2012 on Twitter as a "disaster" and a "car crash" although its own official feed continued to generate tweets as if the event at the Royal Victoria Docks was proceeding without hitches.

Some of the biggest acts in electronic dance music had been brought together at the London Pleasure Gardens in the Royal Victoria Docks, where a 60,000-square-metre outdoor derelict space had been redesigned by the team behind Glastonbury's Shangri-La.

The US rapper Snoop Dogg was billed to headline on Friday night, while Orbital were due to entertain the masses on Saturday. It was the first time that Bloc had been held outside a holiday resort, with Pontin's in Hemsby and Butlin's in Minehead having hosted the festival in previous years.

The continuation of the festival into the weekend appeared to be in doubt as many ticket holders were prevented from entering after queuing for hours, while extra police made their way to the location before midnight to oversee the departure of those inside.

Anger on Twitter gathered around the #bloc hashtag as pictures were relayed of festival goers standing behind crowd barriers with police looking on. Tickets had ranged in price from £55 to £125 and Friday night had been described on the event's official website as a sellout.

Bloc is um a disaster right now. "we're in the middle of a car crash". Could it just be shut down? twitter.com/danhancox/stat… — dan hancox (@danhancox) July 6, 2012

The music writer Dan Hancox reported shortly after midnight that the police had "cut the site in two", tweeting earlier: "Bloc is um a disaster right now. We're in the middle of a car crash."

The reaction of another Twitter user, Rob Gregg, was typical: "Bloc is the worst festival I've ever been to. I don't know how they've managed it."

Another, Lauren Strain, tweeted: "Scary, and very nearly led to injuries; all we were told was 'move back' – where to exactly?"

• This article was amended on 7 July 2012. The original headline wrongly gave the impression that it was police, rather than organisers, who decided to close the festival.

• If you were at Bloc, tell us in the comments thread how it was for you.