According to Malaysia’s The Star Online, the men killed were Myanmar national Tun Tun Win (36), North Korean Pang Chung-hyo (29) and an Indonesian national only known as Kardianto (38).

Of the injured, nine of them were Indonesians, seven were from North Korea, six were from Myanmar, five were mainland Chinese and two were from Bangladesh.

The blast occurred about 450m underground with “sparks” from a switch along with a defective fan being considered a possible cause.

Sri Aman Fire and Rescue Department chief Ranger Moos said a ventilation fan was not working.

“According to the supervisor, the blast occurred when the workers were just about to start work,” he said.

“There was an explosion when a switch for the conveyor belt was turned on.”

About 49 of the 119 foreign workers at the mine were North Koreans.

Asia News Network quoted Deputy Home Minister Datuk Seri Wan Junaidi Tuanku saying the men were employed via a special arrangement between the Sarawak and North Korean governments.

"No local or Sarawakian will dare to take up such jobs; that is why the need for foreign workers,” he said.