QUETTA, pakistan (AP) — A methane gas explosion caused a mine to collapse and kill seven coal miners in southwestern Pakistan, a mining official said Tuesday, the second such incident in the region in less than a week.

The explosion took place Monday night, causing a coal mine to collapse in the district of Harnai in Baluchistan province, trapping several miners, according to a provincial chief inspector of mines, Shafqat Fayyaz.

Fayyaz said rescuers retrieved the bodies of the seven miners who were killed. He said an investigation was ordered into the incident, which came five days after six miners were killed in another mine explosion in Baluchistan.

Safety standards are commonly ignored in the coal mining industry in Pakistan, leading to accidents and explosions that have killed numerous mine workers in recent years.