By Chris Mfula
LUSAKA (Reuters) - Zambian opposition leader Michael Sata was declared the winner of Zambia's presidential election on Friday, ousting incumbent Rupiah Banda as the leader of Africa's biggest copper producer in polls marred by public violence.
Sata, 74 and nicknamed "King Cobra" because of his venomous tongue, toned down his rhetoric against foreign mining firms, especially from China, in the closing stages of the six-week campaign but his victory could still cloud the investment outlook.
Chief Justice Ernest Sakala declared Sata the winner after he received 1,150,045 votes compared to Banda's 961,796 with 95.3 percent of constituencies counted. Sata received 43 percent of the vote.
Rupiah Banda, 74 and leader of the Movement for Multi-party Democracy (MMD) party that has run Zambia since one-party rule ended in 1991, is expected to make a statement early Friday about the vote.
Earlier youths fought running battles with riot police in the towns of Ndola and Kitwe, 250 km (150 miles) north of Lusaka, setting fire to vehicles and markets in the normally peaceful southern African country's mining heartland.
Hackers who hit the Election Commission's website overnight, posting false results showing Sata on course for a landslide, added to the confusion and tension of what was already a neck-and-neck run-off between two old rivals.
(Writing by Jon Herskovitz; Editing by Marius Bosch)