Winamwanga are found in northern Zambia

Zambia

Zambia , officially the Republic of Zambia, is a landlocked country in Southern Africa. The neighbouring countries are the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west....

 and southwestern Tanzania

Tanzania

The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...

. They speak Nyamwanga

Nyamwanga

Mwanga, or Namwanga, is a Bantu language spoken by the Namwanga in the Northern Province of Zambia and in southwestern Tanzania...

 or Chinamwanga. In 1993 the Mwanga population was estimated to number 256,000, with 169,000 living in Zambia and 87,000 in Tanzania http://www.ethnologue.com/show_country.asp?name=TZ.

Winamwanga are said to have originally migrated from Tanzania, although some evidence shows that they can trace their roots to northern Sudan.