Kassala is the capital of the state of Kassala in eastern Sudan. In 2002 its population was recorded to be 957,000. Built on the banks of the Gas…Kassala is the capital of the state of Kassala in eastern Sudan. In 2002 its population was recorded to be 957,000. Built on the banks of the Gash River, it is a market city and is famous for its fruit gardens. Many of its inhabitants are from the Hadendawa sub-tribe of the Beja ethnic group.