THE University of York's Central Hall has been attacked with spray paint and liquid fertiliser during a scientific conference.

A dozen people - believed to be anti-GM crop campaigners targeting Bayer, one of the sponsors - damaged viewing screens, audio-visual equipment, walls and about 50 chairs during a lunchtime break in a Plant Genomics conference.

Delegates were moved to a different building for the afternoon session.

Staff were today attempting to clear up the paint, which was sprayed on walls, screens and audio visual equipment, and the fertiliser, which was poured on about 50 chairs.

University spokeswoman Hilary Layton said: "They have made quite a mess." She said it was not yet known how much the damage would cost to repair, nor when the hall would be available for use again.

This is the second conference at the Central Hall to be hit by protesters over the summer, with the Church of England General Synod disrupted by demonstrators from Outrage, the gay rights group led by Peter Tatchell.

Ms Layton said: "It's a great shame if people cannot come here to discuss issues at conferences without this sort of thing happening.

"People should be able to discuss matters freely without fear of such action, particularly at a university."

One delegate at the Genomics conference said of the protesters: "They seem to be too stupid to realise this conference is not about GM crops."

Conference host Professor Ottoline Leyser said the study of the structure and function of plant genomes was about understanding basic plant biology.

"Of course one application for this information in the future could involve GM crops, but it is mainly important for things like protecting plant ecology and biodiversity.

Police investigating an allegation of assault, following the Central Hall incident, arrested a man near the university.

Updated: 11:02 Friday, September 05, 2003