蜜芽传媒

There is much speculation about the exact cause of the deadly blasts in China's northern city of Tianjin. The China Earthquake Networks Centre said the magnitude of the first explosion was the equivalent of detonating three tonnes of TNT, while the second was the equivalent of 21 tonnes. Andrew Johnston, an explosives expert who works for CBRNE World, shared his assessment.

(Picture: Scene of blast in Tianjin. Credit: EPA)