Sixteen animal rights campaigners are on trial for alleged offences in relation to a protest against Oxford's animal testing laboratory.

The activists from Speak were arrested at a protest last July outside the Sheldonian Theatre during an Oxford University Encaenia ceremony.

Prosecutor Gareth Branston told Oxford magistrates yesterday the protesters were spread across the junction of Catte Street and New College Lane and using a megaphone.

Fearing the demonstrators were causing a serious disruption, police ordered the group to continue their demonstration at Martyrs Memorial in Magdalen Street.

But as the group began to walk away many of the protesters stopped and sat down refusing to move. Mr Branston said: "One of the defendants, Mel Broughton, began to yell and gesture other protesters to hold their ground and protesters as a result sat down.

"Some protesters linked arms with each other and protesters, particularly the 16 defendants, made it clear to the police they would not comply with the conditions imposed."

After police arrested three protesters at the scene the bulk of the remaining demonstrators began to disperse, Mr Branston told the court.

A further 13 were arrested after police reviewed camera footage of the demonstration. Mr Branston added officers used powers contained in the Public Order Act to force the protesters to move.

The protest, at a ceremony where academics receive honorary degrees, was held to campaign against the animal testing laboratory Oxford University is building in South Parks Road.

In court are: Pauline Broughton, 70, of Northampton, Mel Broughton, 46, also of Northampton, Fran Cornwell, 59, of Milton Keynes, Rachel Nelson, 40, of North Wootton, Somerset, Anna Cooke, 31, of High Wycombe, Sheila English, 64, of Bedford, Brett Gordon, 42, of Cross Street, Oxford, Anthony Morrison, 43, of Newcastle, Deborah Scicluna, 46, of London, Emma Speed, 39, of Leigh-on-Sea, Eileen Kinghorn, 43, of Bow, London, Michael Haines, 59, of Cirencester, Trevor Holmes, 50, of Newcastle, Amanda James, 42, of Bluntisham and Joanna Robertson, 29, and Melanie Bates, 35, both from Reading.

The trial continues.