Four men have been charged with attempting to hold a music event without a licence following a rave in a disused warehouse in Suffolk.
Officers were pelted with missiles while trying to eject more than 200 people from the event in Haverhill.
They are due before Bury St Edmunds Magistrates' Court on 11 June following the event on 21 November 2009.
Two Hertfordshire men and one each from Norfolk and Lincolnshire have been charged.
The man from Norfolk has also been charged with possession of cannabis.