Mexican authorities say a helicopter crash killed the male pilot and injured three women, and then police who went to the scene were fired on by gunmen.

A security official for the State of Mexico, which borders Mexico City, says officers responding to a 911 call in Sultepec municipality found the downed helicopter but also armed men in six pick-up trucks. The official said a shootout erupted, but gave no further details.

The official spoke on condition of anonymity because they were not authorized to discuss the case publicly.

Mexico State prosecutors say in a statement that no bullet wounds were found in the dead pilot or the three hospitalized women. The official says the cause of the helicopter's fall Sunday night is still under investigation.