Police detained six people who were believed to be responsible for a coal mine collapse that killed 21 workers in Northwest China's Shaanxi Province last week.

Photo taken on Jan. 13, 2019 shows the Lijiagou coal mine of the Baiji Mining Co., Ltd. in Shenmu City, northwest China's Shaanxi Province. (Photo: Xinhua)

The accident happened around 4:30 pm. local time Saturday at the Lijiagou coal mine of the Baiji Mining Co., Ltd. in the city of Shenmu. At that time, 87 people were working underground. Sixty-six of them were lifted to safety after the accident.

(With input from Xinhua)