Chants of "evil" rang out as around 500 campaigners gathered outside the research centre near Woolley, faced by a wall of police.

Up to 400 officers were drafted in from Essex, Suffolk, Norfolk and Nottinghamshire to oversee the largely peaceful demonstration.

The sounds of whistles and drums filled the air as temporary barriers were rattled and leaflets detailing future demonstrations around the country were distributed.

Pensioners mixed with children and placard-wielding men and women, all calling for the centre's closure.

Pensioner Marjorie Embling had travelled from Durham to take part.

She said: "I don't agree with testing drugs and useless products on animals. I am here to support the protest, however long it takes to get the place closed."

Campaigners began arriving at around noon on Saturday. Most had left by 4pm.

Some moved on to stage smaller demonstrations at addresses in Fenstanton, St Ives, Over and Cambridge of workers thought to be associated with HLS.

A 30-year-old woman from Kent, a 54-year-old woman from Bristol and a 42-year-old man from Essex were charged with breaching an exclusion order on the site.

A 34-year-old man from Bournemouth was charged with a public order offence and a 34-year-old Evesham woman was charged with aggravated trespass.

They are all due to appear before Huntingdon magistrates on Wednesday.

It is estimated the operation has cost Cambridgeshire police in the region of £100,000.

Nobody from HLS was available for comment.

Further to my previous message, several of us 'not so young' protesters are pursuing the matter of police tactics during the protest at HLS on Saturday.

We do not feel the police were justified in charging through a crowd of peaceful protesters, knocking some of them to the ground and violently elbowing others out of the way who were prevented from doing so because of people in front of them. I was knocked into a ditch, another was punched in the kidneys, one fell and hurt her back, and another was sprayed in the face with an unknown substance.

'PREVIOUS MESSAGE'

There was quite a good turnout, I should say about 500-600, which isn't bad when you consider all the other events that were going on.

We congregated outside the gates of HLS and there didn't appear to be such a large police presence as on some previous occasions. There were several speeches including a rousing one from John Curtin. It was very peaceful for a while and then people started to run across the fields to the A1, pursued by police.

I saw one man arrested by about five police who held him face down in the mud while they handcuffed him. Shortly afterwards about 8-10 police formed a group and were obviously planning something, when suddenly one of them pointed in the crowd and shouted "there he is". They charged into the protesters, violently pushing people aside, some of whom were knocked to the ground. One person had something squirted in her face. We don't think it was CS gas, could be pepper dust?.

Their target was John Curtin and people were trying desperately to protect him by getting between him and the police but they caught him eventually and he was arrested, I suspect for incitement although I wouldn't be sure. Apparently he was roughed up whilst being arrested, pressure behind the ears etc. and I think he is feeling a bit bruised. I understand he is out on police bail. It was nice to see so many of the regulars there, and also quite a few people who had not been on a demonstration before.

Pat, Cambridge

"I am not interested to know whether vivisection produces results that are profitable to the human race or doesn't. The pain which it inflicts upon unconsenting animals is the basis of my enmity toward it, and it is to me sufficient justification of the enmity without looking further"
Mark Twain.