The land is largely hot, dry desert. Located in the eastern portion of the federation is a portion of the Jabal al Akhdar Mts. Less than half of the inhabitants of the UAE are Arabs, while South Asians make up about 40%, and there are also Iranians, East Asians, and Westerners. Only about 20% of the UAE's population are native citizens. The nonindigenous population was first attracted by the employment provided by the UAE's petroleum boom. Muslims comprise 96% of the population (80% of these are Sunni, the balance Shiite) and the remaining 4% are largely Christian or Hindu. The official language is Arabic, but Farsi and English are widely used, and Hindi and Urdu are spoken by many of the South Asians.