Police are appealing for calm after three nights of violence at a Berkshire dairy owned by a Muslim family.
The Medina Dairy in Windsor was hit by a suspected petrol bomb on Wednesday evening, on the third night of unrest.
Police have stepped up patrols in the Dedworth area and said they would use "robust policing tactics" to bring the situation under control.
The outbreak of disorder began after a mother and her daughter were set upon by a gang of 20 Asian youths armed with baseball bats, iron bars and pitchforks.
The shaven-headed thugs – all dressed in white robes – launched the attack after pouring out of a former office building which is being used as an unofficial mosque.