Members of the public who were "minding their own business" were physically attacked by the 120 protesters, said police, as were the guests who arrived by car for the Chiddingfold, Leconfield and Cowdray Hunt's end-of-season dinner-dance at a hotel in Walberton near Arundel.
"The hunt protesters were more violent than we have known them in the past... they threw stones and other missiles not only at the people who were attending the hunt ball but also indiscriminately," said Superintendent Phil Clarke of Sussex police, who co-ordinated the 80- plus police officers brought in to contain the violence.
"The most worrying factor is that a number of vehicles which were attacked - at least five - belonged to local people who had nothing to do with the ball."
The hunt has in the past been the target of letter bombs and boobytraps believed to have been sent by animal extremists.
Brian Trafford, a 65-year-old businessman who had flown in from Moscow that day, was caught on the approach to the venue. "We went straight into an ambush. It was a fairly traumatic experience," he said last night.
All his car windows were smashed, and his wife and daughter-in-law were covered in glass as a series of blows rained down on the car. "Someone got onto the bonnet and smashed the windscreen... then my door was wrenched open. Were they going to pull me out? We didn't know what was going to happen next." Eventually, they were able to park and slip into the hotel by a rear entrance.
Other guests were aware that there could be problems, but none had anticipated the degree of disruption. Hunt chairman Martin Reed had been warned by the police that the saboteurs were planning a "mega hit". "The hunt has been targeted before but never to this degree - not this violence," he said.
Outnumbered by the demonstrators, the police were unable to make on- the-spot arrests. "The saboteurs walked around with balaclavas, helmets, whips, sticks and goodness knows what else, but the police let them pass."
A spokesman for West Sussex Hunt Saboteurs, who refused to give his name, said yesterday: "Last night's hunt ball was a celebration of cruelty. Our demonstration represented public opinion slapping back."Reuse content