Azerbaijani government sources have confirmed that a Russian Pantir-S1 surface-to-air missile was the cause of the Embraer E190 crash on Christmas Day.
 

The aircraft, an Azerbaijan Airlines Embraer E190, registered 4K-AZ65, was operating a scheduled passenger service from Baku to Grozny when it attempted to make an emergency landing near Aktau, Kazakhstan.

Video recorded by witnesses shows the aircraft crashing before it reached the airport. Of the 72 passengers and crew onboard, 38 were killed.

According to Euronews, a missile was fired at the aircraft during drone activity and exploded beside the aircraft. The explosion sent shrapnel into the aircraft, even impacting passengers and crew.

At the time, Russian air defense forces were attempting to shoot down Ukrainian UAVs in the area. AnewZ said that during operations such as this, Russian aviation authorities were required to close down airspace to civil aircraft. However, for unknown reasons, this was not done. 

The aircraft was not allowed to land at Russian airports despite the pilots' requests for an emergency landing and was told to fly across the Caspian Sea to Aktau in Kazakhstan. The aircraft's signals were jammed on the way to Aktau. The aircraft reappeared on radar minutes before impact.