The majority of the population is Punjabi (an estimated twothirds). Other major ethnic groups include the Sindhi, Pathan, Baloch, and Muhajirs (immigrants from India and their descendants). The Rajputs and the Jats are the most numerous of the Punjabi castes. In the area of the delta and the lower course of the Indus River are Sindhi peasant tribesmen. In the north and northwest are the hardy, warlike nomadic and seminomadic Pathans. The Balochi live in the vast western section of Pakistan and are divided into 12 major tribes, some of them purportedly of Dravidian origin. Native speakers of Urdu, the Muhajirs are refugees, or descendants of refugees, from pre-partition India. They are well represented in the cities.