A military helicopter crashed in northern Mexico Saturday, killing all 11 people on board, the Defence Department said, dpa reported.
Poor weather was blamed for the crash of the Bell 412 helicopter in Durango state.
President Felipe Calderon has sent thousands of soldiers to the region in the fight against drug cartels.
Some 300 people were killed due to drug violence in the last week alone in the bloodiest week yet in Mexico, the daily Reforma newspaper reported. More than 5,200 people have been killed this year.