At least 37 people have been killed in an explosion at a fireworks factory in China's Hunan province, state broadcaster CCTV reports.

One person is missing, 51 people are receiving medical treatment in hospital, and five of them are in critical condition.

Earlier, 26 people were reported dead.

The explosion at the fireworks factory in Liuyang, Hunan province, occurred on Monday. The wave of the blast damaged buildings within a radius of 300-400 meters from the factory.