KUNMING - Rescuers decided to stop the search for eight miners Sunday who have been trapped underground for 10 days in a coal pit after a gas leak accident in Southwest China's Yunnan province, saying they had no chance of survival.

The accident occurred at the Sizhuang Coal Mine in Shizong county of Qujing city on the morning of Nov 10, when a powerful gas outburst hit an underground platform and then another. A total of 43 miners were trapped and 35 bodies have so far been retrieved.

Although rescuers had confirmed the location of the other eight miners, the "dangerous" underground situation forced them to stop the rescue work, said Li Jianjun, secretary-general of the Qujing municipal government.

A high density of gas, poor visibility, narrow space and potential dangers of coal-dust explosion and detonator explosion in that work platform threaten the safety of rescuers, Li said.

"Experts believe the eight trapped miners have no chance of survival under such circumstances after more than 240 hours. So we decide to give up the search," he said.

Hundreds of rescuers had been mobilized to join in the rescue operation over the past days.

Local procurators had earlier said initial investigation found four officials in charge of coal mine safety were to 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 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.