An explosion inside a coal mine in southwest Pakistan has killed at least 18 miners and trapped 24 others underground as rescuers race to reach the survivors. The blast apparently was triggered on Thursday by a buildup of methane gas and occurred on the outskirts of the Baluchistan provincial capital of Quetta, government mine inspector Ghani Baloch said. The bodies of the seven miners initially were recovered hours after the deadly blast, and emergency responders later found 11 more bodies, officials and a provincial disaster management agency said in a statement. Baloch said rescue operations would continue until all the trapped miners were found, but he indicated that officials believed the death toll likely would rise further. “The chances of finding anyone alive diminish after methane gas explosions because oxygen levels drop to zero, and rescuers are also proceeding cautiously inside the mine,” he said. He pledged that the provincial government would go all-out in the continuing response.