A study has found that nearly 400 hazardous incidents occurred over a three-month period early this year at Queensland mines and quarries.

The 397 incidents in the study involve fires, explosions, car collisions and injuries to workers, the Department of Mines and Energy said.

For the period between February and April 2009, over 32% of all incidents involved vehicles on mine sites, abc.net.au reports.

Two accidents occurred because drivers fell asleep when driving while 56 incidents happened when vehicles lost control.