Five people were killed Thursday afternoon by carbon monoxide poisoning when they were mining illegally at a closed-down coal pit in north China's Shanxi Province, local authorities said Friday.

The accident occurred at 4:00 PM in a village of Yuanping City. The pit had previously been sealed off, according to the municipal government.

Three other poisoned people were hospitalized and were in stable condition, it said.

The police were further investigating the case.

(Xinhua News Agency February 20, 2010)