POLICE were shocked by the unprecedented level of violence ravers at a party in Rodbourne’s River Ray Industrial Estate showed officers last night.

Hundreds of revellers from as far away as Luton, Dunstable and Basingstoke entered an empty unit next to the CB Autos dealership in Barnfield Close in the early hours of Sunday morning in an underground rave rumoured to have been planned up to two weeks ago.

Around 70 officers from Wiltshire Police were assisted in controlling the incident with 26 officers from Avon and Somerset Police – including five dog handlers - and officers from Thames Valley Police.

But this did not deter party-goers, with up to 200 people continuing  to try and break through police blockades to join the 90 to 100 people already inside until around 8am.

Four officers were injured at around 6am when the incident escalated, with revellers hurling missiles in the form of stones and bottles.

One officer was concussed when he was hit with a slab of concrete.

Meanwhile, one member of the public also received a head injury and two or three were taken to the Great Western Hospital after receiving bites from police dogs.

Police were issued with batons to try and control the incident and while several officers had taser as part of their standard equipment, police were unable to confirm whether it had been deployed during the fracas.

Superintendent Andrew Carr said he had not seen anything of this nature of violence in Swindon before.

He said: “We do get reports of raves happening but never something this large or with such levels of violence here before.

“"It is very disappointing that members of the public became hostile to officers and began to throw missiles and damage fences and property. 

“We do monitor social media but we were only first aware of something taking place at around 1am when we became aware of increasing volumes of traffic.

“Nationally there are systems in place to monitor and try and prevent illegal raves taking place.”

Music finally stopped blaring from the unit shortly after 9am, and police were able to start clearing the site at around 11am.

Four people were arrested for public order offences and one for assaulting a police officer.

Police seized a large quantity of speakers and sound equipment.  It is not yet known whether there were any drugs present to be seized.

Police also confirmed some fencing had been damaged during the night.