Zambia's ruling party candidate led in partial returns from a presidential election in the southern African nation, election officials said Thursday.

Edgar Lungu of the Patriotic Front party was ahead with 50 percent of the vote after 80 out of 150 constituencies were counted, according to results released by Zambia's election commission. Opposition leader Hakainde Hichilema of the United Party for National Development was second with 45.1 percent of the vote.

The election was held Tuesday to replace President Michael Sata, who died in October after a long illness. The winner will serve out Sata's term until elections next year.

Copper-rich Zambia has been led since Sata's death by acting President Guy Scott, a white Zambian of Scottish descent who was not a candidate.