CASINO RAID: Macau police said they arrested 150 people in raids at casinos and hotels across the Chinese territory following a spate of violence that raised fears of a revival of gang warfare in the world's most lucrative gambling market.

DETAILS: Police questioned 1,300 people in an exercise named "Operation Thunderbolt 2012." They would not name the casinos or hotels involved.

CONTEXT: Macau, an hour by ferry west of Hong Kong, is the only place in China where casino gambling is legal. Companies operating casinos in Macau include Las Vegas Sands Corp., Wynn Resorts Ltd. and MGM Resorts International.