Update: At least 13 dead and hundreds injured in huge explosion in Chinese city

Update: At least 13 dead and hundreds injured in massive explosion in Chinese city

At least 13 people have been killed, and hundreds have been wounded in a massive explosion at a warehouse for dangerous materials in a major city in northeastern China.

Videos of the huge blast have been posted online, with footage showing a dramatic fireball inTianjin, which American researchers say could be seen from space.

The explosion - which could be felt 10 kilometres away - created a huge mushroom cloud.

According to Chinese broadcaster CCTTV, the numbers of wounded are increasing, and 300 - 400 people have been reported injured so far.

Heartfelt Prayers go out to the people effected by the #Tianjin explosion. http://t.co/cCWGL7Segz pic.twitter.com/vqVYFORdwg

— Rick Saake (@nternetbiz) August 12, 2015

The explosion was so powerful that it was picked up by weather satelites.

VIDEO: #Tianjin explosion apparently captured by Japanese weather satellite. https://t.co/a7uNugkq22 h/t @RobDotUK

— reported.ly (@reportedly) August 12, 2015

Two firefighters battling the blaze are reported missing and six are injured.

According to CCTTV, the National Business Daily newspaper has reported that six fire brigades are on the scene and the fire has almost been extinguished.

Tianjin is a major port city in northeastern China, with a population of 7.499 million, according to UN data from 2000. It is China's fourth most populous city.