Rescuers have pulled 23 miners in northeast China to safety after a blast at an iron mine trapped them underground and killed 11 others.

The official Xinhua News Agency said two workers remained missing Wednesday after explosives that were being transported to a mine blew up near the entrance Tuesday afternoon in Benxi, a city in Liaoning province.

The explosion damaged the mine shaft that was more than 1,000 meters (3,300 feet) deep, trapping 25 workers who were underground. Eleven workers were killed instantly and nine were injured.

China's mines were long the world's deadliest, although steady improvements in regulations, safety training and equipment have reduced the toll. Liaoning province has seen its share of accidents, including a dust explosion in 2014 that killed 28 miners and injured 50.