NINGBO -- Two people were killed and many injured in an explosion at the site of a demolished factory in the city of Ningbo in East China's Zhejiang province Sunday, according to local authorities.

More than 30 people were taken to hospital, with two injured seriously, after the accident which occurred 8:50 am in Jiangbei district, local authorities said

Local police said many nearby residential communities were affected by the explosion.

An investigation is underway.