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.

Brazilian investigators have reportedly begun analyzing black boxes of the Azerbaijan Airlines Embraer E190 involved in the crash. The news comes almost two weeks after the regional aircraft operating flight J28243 from Baku to Grozny crash-landed near the city of Aktau in Kazakhstan, killing 38 people.

The extraction of flight data from the Brazilian-made Azerbaijan Airlines 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.

Black boxes from plane crash will be delivered to Aeronautical Accidents Investigation and Prevention Center (CENIPA) in Brazil, says Kazakh Transport Ministry - Anadolu Ajansı

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.”

The flight recorders of the Azerbaijan Airlines aircraft that crashed at the airport in Aktau, Kazakhstan, will be sent to Brazil for decoding. Source: Ministry of Transport of the Republic of Kazakhstan on Telegram Quote: "According to the standards of Annex 13 of the Chicago Convention,

Authorities in Kazakhstan say the flight recorders from an Azerbaijani plane that crashed last week will be sent to Brazil for investigation.

The voice recorders from the Brazilian-made plane were analyzed in Brasilia before the data was handed to Kazakh authorities. Meanwhile, Azerbaijan has directed unusually strong words towards Moscow.

Azerbaijan Airlines flight J2-8243 from Baku ... crash would become known after the data from flight recorders sent to Brazil is accessed.

Indonesia on Monday officially joined the BRICS bloc of developing nations, marking a significant expansion of the group's global influence.

Kazakhstan finds itself caught between Russia and Azerbaijan as it investigates a jet crash that has ignited tensions between its two neighbors.