SHANGHAI (Reuters) -China's State Council Security Committee and municipal and provincial governments have held emergency video conferences and issued warnings about fire hazards and safety in the wake of a blast in China's northwest that killed 31 on Wednesday. Separately, China's Ministry of Culture and Tourism issued an emergency circular, urging all localities in the country to investigate "hidden dangers" and strengthen supervision and inspection. Wednesday's explosion at a BBQ restaurant prompted President Xi Jinping to order a safety overhaul across China, calling on all regions to rectify safety risks.