Historically, the city was an important center for the religion of and the home of several communities from and the Baku has been highly-coveted for centuries by various empires, in large part because of its natural harbor and vast petroleum resources.
Baku and the rest of Azerbaijan were part of the USSR until it collapsed in 1991.
The explosion at the Location club in Baku was believed to have been caused by a gas leak but the investigation was ongoing, interior ministry spokesman, Ehsan Zahidov, told Associated Press.
New oil infrastructure was developed, including the Azeri-Chirag-Guneshli field and the Shah Deniz gas field.
The emergency services issued a statement saying firefighters were called to the club in the centre of the city at 3am and extinguished the fire before it could spread.
The city is also home to metalworking, shipbuilding and repair industries, electrical machinery manufacturing, the production of chemicals and construction materials, and food processing.