A blast in a Chinese coal mine killed at least 20 people and trapped another 30, Xinhua news agency said. "A gas outburst hit a colliery in central China's Henan Province," the agency said. The explosion occurred in a pit owned by Pingyu Coal & Electric Co. Ltd. based in Yuzhou City. Rescue operation is ongoing. The accident in Chinese coal mine came two days after all 33 Chilean miners, trapped more than 600 meters underground for over two months after a rock collapse have been freed. The coal industry in energy-hungry China is one of the most dangerous in the world due to poor work safety standards and intensive work schedules. Some 7,000 lives are lost annually in accidents at coal mines in the country.