A powerful gas explosion tore through an underground coal mine in northeastern China killing 31 miners and trapping 82, state-run China Central Television (CCTV) said, accoorfing to the foreign media.

In one of the deadliest incidents in a mine, the blast occurred at Xinxing mine in Heilongjiang province at 2.30 am, trapping 118 workers. The CCTV said a total of 528 miners were working in the mine at the time of the explosion, but 390 people managed to escape to safety.

The television network said 31 people died on the spot while others were trapped in the mine, which is one-thirds underground. The explosion was caused by a gas build-up.

Xinhua said the Vice Premier Zhang Dejiang was rushing to the spot to direct the rescue operations. The mine is owned by a private company based in the provincial capital Harbin.

China has a dismal record of mine safety with thousands of people every year in mine accidents. International NGOs have labelled Chinese coal mines as the most dangerous working places in the world, with safety standards often ignored for quest for profits and to meet targets set by the provincial committees. According to official figures available on Chinese websites, more than 3,200 workers have died in collieries last year, but international NGOs put the figure as almost double.