Firefighters battled Thursday to extinguish a blaze that engulfed a 12-floor wholesale market building in northwest China and likely caused casualties, a firefighting official said. Flames and smoke engulf the 12-storey wholesale market building in Urumqi. The fire in downtown Urumqi, the capital of Xinjiang region, had been burning all night after it started in a building that normally has more than 2,000 people selling clothes, toys and various commodities, the state-run Xinhua News Agency said. "We are trying to put out the blaze. There must be some casualties, but we're still not sure about the number," said an official at the Urumqi Fire Office. Xinhua said 181 firefighters and 48 fire engines were trying to contain the fire. It was not known how it started. Guests in an adjacent 20-storey hotel were safely evacuated, Xinhua said.