At least seven people were killed and hundreds were injured in massive explosion in Tianjin, a metropolis in northern China, on Wednesday midnight. [ Tianjin Blast Photos]

Chinese state media reported that the explosion occurred after a shipment of explosives blew up at about 23:30 (16:30 GMT). One report said at least 400 were injured in the blast. The Daily Mirror reported claimed that more than 1,000 suffered injuries. 

It is claimed that the impact of the blast was felt within 10 km radius of the port city.

Eyewitnesses said that they heard a huge explosion, followed by a massive ball of fire. Several images of the explosion shared on social media show a huge mushroom cloud at the site of inferno in Binhai New Area.

The explosion created tremors equivalent to a 2.9 magnitude earthquake. The blast it is said was so big that it can could seen some space.

People trying to ascertain the cause of the blast initially came up with several theories. A social media user claimed that the blast took place at the Ruihai hazard material warehouse near the Tianjin port. Some reports said that the explosion occurred at a gas station in Tianjin.

Some rumours on social media even claimed that the blast was triggered after "Perseids" meteors hit the city. 

Tianjin explosion video