'I was scared. ... Was it an attack or something? We had no idea'

Witnesses told of their shock on Thursday following the explosions that rocked Tianjin late on Wednesday evening.

Stefan Andersen, a Danish citizen working for FH-International, an international engineering company in Tianjin, said he was awoken by the sound of an explosion.

"My apartment is just 1 kilometer away. I went to the window and then there was another explosion. I was really shocked, and I knew something was not right. I quickly put on some clothes and went downstairs into the street.