Local Chinese authorities say three people have died and six were hospitalized after being poisoned by gas in an illegal gold mine.

The official Xinhua News Agency says rescuers were dispatched to the mine in Songxian County in the central province of Henan on Saturday after a tipoff from the public.

In a report Tuesday, Xinhua said the mine had been abandoned, but local farmers were trying to extract remnants of gold from it with the use of chemicals such as sodium cyanide. They were then apparently overwhelmed by the gasses released.

Xinhua said the case remains under investigation. Tuesday was a national holiday and calls to the local government rang unanswered. No official notice was posted on the county's website or official microblog.