The violence in the coastal city of Masoura, north of Cairo, began today when opponents of President Mohammed Mursi pelted his supporters with garbage as they gathered outside a mosque to stage a march to back the president.
The officials spoke on condition of anonymity because they were not authorised to speak to reporters
Clashes between the two sides have grown in frequency over the past few days during the buildup for June 30 protests by the opposition to try to force Mursi out.