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.

The second black box has been found at the plane crash site near Aktau and handed over to the investigation department, according to a Kazakh official from transport department on Thursday. The Embraer 190 aircraft operated by Azerbaijan Airlines flight J2-8243 from Baku to Grozny crashed near Aktau Airport in Kazakhstan on Wednesday.

Survivors of the Azerbaijan Airlines plane that crashed in Kazakhstan reported hearing thuds and explosions from outside the aircraft during the flight, as the cause of the deadly catastrophe remains under investigation.

Azerbaijan Airlines flight J28243, which was heading from Baku to Grozny, crashed near Aktau Airport in Kazakhstan. Videos on social media show the aircraft descending quickly and crashing on the ground in a ball of fire.

The Azerbaijan Airlines flight was en route from Baku in Azerbaijan to Grozny in Russia, but was rerouted due to fog and crashed near the Aktau airport. A video from Turkey shows a cargo ship rolling onto its side at a port in Istanbul after an imbalance in the cargo load.

Azerbaijan's president accused Russia of trying to cover up its role in a plane crash that killed 38 people. Preliminary results of Azerbaijan’s investigation into the crash indicated that a missile from a Russian air-defense system hit the aircraft.