By Chris Mfula
LUSAKA (Reuters) - A slow count delayed the first results from Zambia's presidential election which remains too close to call, officials said on Wednesday.
Michael Sata, leader of the opposition Patriotic Front (PF) and a critic of Chinese mining investment, went head-to-head against President Rupiah Banda of the Movement for Multi-party Democracy (MMD) in Tuesday's election in Africa's top copper producer.
Counting was slower than expected after a series of technical glitches delayed voting in parts of the capital, Lusaka, on Tuesday, sparking disturbances. Police said they had made 19 arrests.
"Our results are announced by constituencies. We have received results but none of them make up a constituency," said Electoral Commission of Zambia spokesman Cris Akufuna.
Full national results may not come until Thursday.
One opinion poll published before the September 20 vote gave Banda a slender lead over his rival, whom he beat by just 35,000 votes, or two percent of the electorate, in a 2008 presidential run-off.
Sata's main support is in Lusaka and the northern Copper Belt, both of which are likely to report results before the countryside where Banda claims most of his backing.
"The picture is still likely the same as it has been in the past, with the PF being favored in urban areas and the MMD having an upper hand in rural areas," said one election monitor who declined to be identified. "It is still very close to tell the winner."
PF officials said it had fared surprisingly well in the countryside while the pro-Banda camp said the MMD had made unexpected gains in urban areas.
DaMina Advisors, a consultancy that specializes in African capital markets, said Sata was poised to oust the MMD for the first time since the end of the one-party state in 1991 due to support from young voters demanding change.
"The over 1 million new voters who will be casting their ballots for the first time are expected to back Sata's populism over Banda's status quoism," DaMina said in a note.
However, research firm Eurasia Group said it expected Banda to see off Sata's challenge thanks to a healthy economy and recent surge in government revenues from the privatization of telecoms group Zamtel and back taxes from mining companies.
Eurasia said another narrow loss for Sata could cause disgruntled supporters to take to the streets, but it predicted any unrest would have no impact on what is regarded as one of sub-Saharan Africa's most promising economies.
"If Sata loses a close election and rejects the outcome there will be some unrest in Lusaka and the copper belt but it will be contained and relatively short-lasting," Eurasia said.
(Reporting by Chris Mfula; Writing by Ed Cropley; Editing by Robert Woodward)