74 workers have been killed and dozens more trapped underground after a gas blast at a Chinese coal mine.

It was the worst accident to hit the nation's mines in more than a year.

More than 400 miners were on the job when the explosion ripped through the mine last night.

Some of the victims died after being rescued from the mine, it said.

Some of the miners trapped at the site outside Taiyuan, capital of the main coal-producing province of Shanxi, reportedly called their families on mobile phones from underground.

The death toll makes this the most lethal accident reported in China's disaster-prone mining industry since 105 people died in a mine explosion in December 2007, also in Shanxi.

President Hu Jintao and Premier Wen Jiabao issued instructions to do everything possible to save those still trapped inside the mine, state television reported.

Dozens of rescuers are searching for those still missing.