Chinese police have formally detained nine people involved in a power plant construction project in the east of the country which collapsed last week killing 74 people, state news agency Xinhua said on Monday.

The accident happened on Thursday morning in Fengcheng, in Jiangxi province, during work on a cooling tower for a coal-fired power plant. A tower crane collapsed, triggering the collapse of the entire construction platform.

Xinhua said the nine included the chairman of Hebei Yineng Tower Engineering, whose family name they gave as Zhang.

State media has said the company was in charge of the building project.