Zambian opposition leader Michael Sata was still leading on Saturday in an election to head one of Africa's most stable and economically successful countries, but acting President Rupiah Banda appeared to be narrowing the gap, Reuters reports.
Sata had 570,460 votes against 543,441 for Banda, election officials said after results from 108 of the 150 constituencies. Some 3.9 million people were registered to vote in the world's 10th largest copper producer.
Banda, whose tally improved with results from his rural strongholds, is a prominent businessman with wide government experience and has campaigned as a steady hand who can maintain the late President Levy Mwanawasa's business-friendly policies.
Thursday's election was triggered by Mwanawasa's death in August from a stroke.
Sata, who has accused the ruling Movement for Multi-Party Democracy of rigging the vote, portrays himself as a champion of the poor and has said if elected he would act to get foreign companies to sell equity stakes to Zambians.
The leader of the opposition Patriotic Front lost a 2006 presidential election against Mwanawasa, who had a strong record of fiscal discipline and cracking down on corruption, two rare successes in Africa. Mwanawasa was praised by Western donors.
The army has been put on alert to prevent any post-election trouble and its head has said he would not tolerate violence.
Zambia's largest independent election monitoring group said on Friday the poll had been generally peaceful but that there were some instances of voting irregularities.
Leon Myburgh, a Johannesburg-based analyst who covers sub-Saharan Africa for Citigroup, said it was no surprise that Sata was leading in early results.
"Sata's support is in the urban areas and results in those areas are usually counted first," said Myburgh. "This is what happened in 2006. Then he was also ahead early."
The vote is a test of Zambia's commitment to multi-party democracy, restored in 1990 after 18 years of one-party rule under Kenneth Kaunda, but neither Banda nor Sata is expected to reshape the political landscape dramatically.
Zambia's economy has grown at an average of 5 percent a year since 2002, boosted by the sharp rise in world commodity prices, and inflation has fallen from more than 200 percent in 1991 to 14 percent.
Both candidates have vowed to take on the huge challenges still facing Zambia.
Sixty-five percent of the country's 12 million people live on less than $1 a day. More than a million are HIV-positive and about 370,000 are in need of antiretroviral therapy.