They cleaned out London jeweller Anderson Jones and were targeting a second jewellery stand when an alarm alerted security men who confronted the gang.
The raiders turned a fire hydrant on the security staff and threw furniture at them as they retreated through a door they had opened from the inside.
Two further gang members were outside with three vehicles and the thieves were caught on external security cameras as they sped off. Any information should be directed to Gloucestershire Police on 0845 0901234.
Masked gang strike at fair
SIX masked raiders broke into the South Cotswolds Antiques Fair at Westonbirt School, near Tetbury in Gloucestershire around 3am on the morning of Sunday August 15 and escaped with an estimated £400,000 worth of jewellery.
