At least 70 people have been killed and dozens have been injured after a huge fire broke out in an apartment building complex which was being used as a chemical warehouse in an old part of Bangladesh's capital Dhaka. Authorities believe that a gas cylinder was responsible for the outbreak of the blaze, which quickly spread through the five-story building where highly flammable chemicals were stored. The injured, at least 45 people, were immediately rushed to hospital, some in very critical condition.