Eleven of them are in the intensive care. A nearby hospital building and other structures as well as cars were also been badly damaged. Pictures from the scene showed widespread damage, with windows blown out of buildings, dense grey smoke engulfing the streets and bloodied people, some lying on the ground. Authorities had detained the owner of the building. Searches for the incident on Chinese social media were blocked on Tuesday. Industrial accidents are common in China, where safely regulations are often flouted. A series of powerful explosions last year at a chemicals warehouse in the northern city of Tianjin killed 165. There have also been cases of people deliberately setting off blasts to settle local grievances such as land disputes.