Hyderabad is the capital of the Indian state of Andhra Pradesh. It is located on the banks of the Musi River in the Deccan Plateau in southern India. The city has an area of 650 square kilometres (250 sq mi) with a population of 6.8 million, and the metropolitan area contains 7.7 million residents, making it the fourth most populous city and the sixth most populous urban agglomeration in the country. The city was expanded in 2007 to form the Greater Hyderabad Municipal Corporation. As a growing metropolitan city in a developing country, Hyderabad confronts substantial urban pollution, traffic congestion, overpopulation and other logistic and socio-economic problems.