- The crash occurred in southwestern Mexico
- One survivor is in intensive care
Three police officers and a pilot died Tuesday when the aircraft went down in Michoacan state, Gov. Silvano Aureoles tweeted.
At the time, Aureoles tweeted that criminals downed the aircraft. But in a later interview with CNN affiliate Televisa, he said he "cannot confirm that it was taken down, or shot down."
An investigation is underway to determine the cause of the crash.
A survivor of the crash is in intensive care, and will be instrumental in helping determine what happened, the governor said.
The helicopter was supporting an operation in the Apatzingan region that has difficult land access, Aureoles said. The operation targeted leaders of criminal cells.
Michoacan has long been a flash point in Mexico's drug war
, and battles between criminals and security forces are a common occurrence.
In May 2015
, a shootout left 42 gunmen and one federal police officer dead.
In July, the mayor of Pungarabato
, a small town in Mexico's Guerrero state, was killed in a shooting on a highway in Michoacan.