Residential building explosion in south China, casualties unknown

SHENZHEN, Dec. 11 (Xinhua) -- An explosion occurred Wednesday in a residential building in the city of Shenzhen, south China's Guangdong Province, according to local authorities.

Local fire and rescue services said they received the report at 2:46 p.m. and sent 16 fire engines and 80 firefighters to the site in Nanshan District of the city.

Further investigation is underway.