Russia has started cooperating with Azerbaijan in investigating the crash of an Embraer 190 aircraft. Officials from four countries will conduct a comprehensive investigation into the cause of the crash,

Two U.S. military officials told NBC News that they had intelligence indicating that Russians may have misidentified the plane and shot it down.

The probe into the Azerbaijan Airlines crash in Kazakhstan is examining the conduct of air traffic controllers after the aircraft encountered difficulty, a source said.

Azerbaijan’s President Ilham Aliyev has accused Russia of accidentally shooting down an airliner on Christmas Day in a disaster that killed 38 people, and covering up the cause.

Azerbaijan's president has accused Russia of shooting down a plane that recently crashed under controversial circumstances. The allegation comes amid heightened tensions in the region, with both countries exchanging accusations over security and sovereignty issues.