QUETTA: A gas explosion in a coal mine on Sunday morning left six colliers trapped under debris. Rescue teams have reached the site and started conducting an operation to save the coal miners. Chief Inspector of Mines Iftikhar Ahmed told the media that the incident happened in Sanjadi area of the province, which is 70 kilometers from Quetta. Ahmed ensured that the miners will be rescued in an hour or two. Casualties in coal mining incidents have become very common in Pakistan. At least 23 miners were killed, on May 6th when two coal mines collapsed near Quetta.