KUNMING - One more body was retrieved Tuesday morning from the shaft of the Sizhuang Coal Mine in southwest China's Yunnan province, bringing the death toll from the gas leak to 35.

The body was found at 0:10 am, confirmed local authorities. Rescuers are busy searching for eight miners still missing in the mine, which is located in the county of Shizong near the city of Qujing.

According to Li Dangrong, vice head of the public security bureau of Qujing city, more than 400 police are involved in the rescue operation and organizing relatives of the victims to identify the bodies.

Wu Hongze, deputy procurator-general in Qujing, said initial investigation found four officials in charge of coal mine safety are to be blame for dereliction of duty. The four, including Sun Zhongqiao, vice head of the coal industry administrative bureau of Shizong, have been detained and further investigation is underway.

The accident occurred at about 6 am last Thursday when a powerful gas outburst hit two underground platforms, trapping a total of 43 miners.

The mine was operating illegally, having had its license revoked a year ago, according to a statement from the provincial coal safety supervision bureau. The bureau ordered the mine to stop production in April.

Four bosses of the mine had been detained at the time for lax mining safety.