A security guard has been convicted of helping dump eight pigs' heads and fake blood outside an Exeter mosque two days after the 11 September terrorist attacks.

Christopher Williams had denied two counts of criminal damage at the Islamic Centre Mosque in York Road, Exeter on 13 September.

A banner which read: "the blood of the American people is on the hands of every Muslim" and ended "Nuckem George" was also erected.

Centre chairman Mohammed Ahmed received two midnight telephone calls saying: "The blood of American children is on your hands".

Muslims are forbidden to eat or touch pigs

The following day a note was found pinned to the mosque's door reading: "This is the start of the end for all Osama bin Laden supporters."

Mr Ahmed told Exeter Magistrates' Court they viewed the incident as being "a gross racial attack on our community".

Three men were seen outside the mosque on the evening of 13 September.

The court heard that Williams's fingerprints were found on the note and when asked by police to spell 'nuke' he wrote 'nuck', as it appeared on the banner.

Williams had claimed he touched the note when it was shown to him by three men in a pub and said he was not a racist and had worked in a mosque.

But magistrate George Tout said today the evidence showed Williams was jointly involved in both offences with others.

Williams, 37, of Merrivale Road, Exeter will be sentenced on 5 September.

After the case a spokesman for Devon and Cornwall Police said: "It would have been a very cruel attack at any time, but more so because of the events in America."