BEIJING - Six more people were detained by Chinese authorities over the deaths of 74 workers in the collapse of a platform in a cooling tower at a power plant, one of the worst work safety disasters in China in recent years.

A total of 15 people have been reported by state media to be under detention after the collapse last week in eastern China's Jiangxi province. The official Xinhua News Agency said the latest detentions Tuesday included two people accused of "selling shoddy products," but did not detail what those products were.

The board chairman of the engineering firm building the plant was already detained, as well as top engineers on the project.

Labourers were building a circular cooling tower when the interior scaffolding collapsed, causing a large amount of steel, concrete and wooden planks to cave in.

The incident prompted calls from government officials for stepped-up inspections and a renewed emphasis on worker safety. Chinese President Xi Jinping said local governments should learn from the accident and hold accountable anyone responsible.

No formal charges have been announced against the 15 people detained. But in other industrial accidents with mass casualties, China has arrested and prosecuted company executives and local officials, with their confessions often broadcast on state television, as part of a longstanding effort to fight deep public skepticism about widespread corruption and poor enforcement of safety standards.