ZHENGZHOU - Four people died after a furnace collapsed at a construction site in Central China's Henan province on Sunday, local authorities said.

The accident happened around 6:10 am at Henan Junhua Development Co, Ltd, in Zhumadian city, sources with the city's publicity authorities said.

The four workers, all from Zhengzhou Hongxin Thermal and Insulation Material Company, were buried after part of the furnace collapsed, sources said. They were found dead after being recovered at 9:50 am.

The company produces melamine and has an annual capacity of 60,000 tonnes.

An investigation into the cause of the accident is underway.