In the crash’s aftermath, Azerbaijan has unleashed rare and stinging criticism of Russia, with the country’s president saying Moscow’s response has caused “surprise, regret and rightful indignation.”

Azerbaijan Airlines flight J2-8243 caught fire as it tried to make an emergency landing in Aktau, southwestern Kazakhstan, on Wednesday. It was traveling from the Azeri capital Baku to Grozny, the capital of the Russian republic of Chechnya.

Azerbaijan Airlines, the carrier of the passenger jet that crashed in Kazakhstan on Christmas Day, said preliminary investigations have found the disaster occurred “as a result of physical and technical external interference,

Authorities in several countries are working to determine what caused the deadly crash of a passenger plane yesterday in Kazakhstan. Russian aviation officials initially blamed birds, but investigators are now focusing on the possibility that a Russian air defense system struck the plane.

Azerbaijani President Ilham Aliyev on Sunday demanded that Russia admit that it fired at an Azerbaijan Airlines passenger jet before it crashed, accusing Moscow of initially trying to cover up the cause of the fatal disaster.

Following Azerbaijan's president calling for Moscow to accept blame for downing an Azerbaijani plane, there is growing public anger toward Russia for its apparent attempts to sidestep responsibility for the incident.

The extraction of flight data from the Brazilian-made Azerbaijan Airlines plane that crashed in Kazakhstan last month was completed at a lab run by Brazil's air force, according to a statement released by the entity on Monday.

Azerbaijan’s leader on Monday accused Moscow of carrying out a “cover up” over a passenger jet crash last month that claimed 38 lives, as relations sour between the two neighbors.