Nine people were hospitalized after a gas explosion ripped through a residential building in Dalian City, northeast China's Liaoning Province, on Tuesday night, according to local authorities.

The accident occurred after 8 p.m. It took one hour to extinguish the flames. 

The building has been completely evacuated. 

An investigation into the cause of the blast is underway.

(CGTN's Guan Yang also contributed to the story.)