Chinese authorities say the confirmed death toll from a coal mine explosion this week has risen to 66, with another 82 miners still missing.

Officials say the chances of finding any more survivors of Wednesday's blast in central Henan province are growing slimmer.

Nearly 450 workers were in the mine near the city of Xinmi at the time of the explosion. Some 300 managed to escape.

Chinese sate-run media report that President Hu Jintao and other top officials have urged local authorities to do everything possible to find the missing miners and determine the cause of the explosion.

China's coal mines are among the world's deadliest. Beijing says more than 4,100 people died in floods, explosions and other coal mine accidents over the past 12 months.

Some information for this report provided by AP and Reuters.