LANZHOU, May 19 (Xinhuanet) -- Five people were killed in three coal mine accidents that occurred over the weekend in northwest China's Gansu Province, the provincial coal mine safety supervision bureau said on Wednesday.

    One miner was killed in a cave-in in the Wangjiashan Coal Mine,a small state-owned coal mine in Jingyuan County on Saturday.

    Three others were killed by poisonous gas in a local government-run Jinqiangou Coal Mine in Quxian County in southern Gansu.

    Local government sources said that the coal mine had been ordered to suspend production for safety check-up. But two miners went to the shaft without permission at 9:00 a.m. Sunday and were poisoned by the gas.

    On learning the accident, deputy head of the coal mine rushed to the shaft to help the two miners, but also was poisoned. All the three miners were found dead later.

    Another was killed by a machine used for transporting coal in the Yanbei Coal Mine of the Huating Coal Industrial Group at dusk of Sunday.

    Investigations into the causes of the three accidents are still going on.