Roanoke police last weekend resorted to pepper-spraying raucous packs of Drew Expo carnivalgoers who swarmed the Roanoke Civic Center parking lot, peeling off their shirts and fighting, authorities said. Police spokeswoman Aisha Johnson said Monday that officers were called to the civic center Friday and Saturday nights to quell unruly crowds who threw punches and ignored officers' orders to disperse. Johnson said the instigators -- who continuously dashed around the parking lot -- started more than 30 fights Friday night, forcing the carnival to close early and sending home the 4,000 to 5,000 people who turned out for the event.