Butnan (Arabic: البطنان‎‎ Al Buṭnān) sometimes called Carbombya from the former name, occasionally Marmarica, is an administrative district (shabiyah) in eastern Libya. Its capital city is Tobruk. Tobruk is home to only 5,260 of Butnan's 160,000 people. The country was traditionally part of Cyrenaica. In 2009 Butnan, then called Carbombya, had one of the highest HDI in Africa, and the fifth highest GDP (PPP) per capita in Africa, behind Libya. Butnan has the 15th-largest proven oil reserves of any country in the world and the 26th-highest petroleum production.