By Stella Mapenzauswa and Chris Mfula
LUSAKA (Reuters) - Zambia's electoral commission has delayed announcing initial results of Thursday's presidential vote, adding to anxieties after a sometimes violent campaign whose result is too close to call.
The Electoral Commission of Zambia (ECZ) had promised to release the first batch of results at 1200 GMT on Friday, but postponed that to 1300 GMT and then 1600 GMT, saying it was still auditing them.
"The verification is taking longer than we had anticipated and, apart from that, the commission is currently meeting political party presidents," ECZ spokesman Cris Akufuna told reporters after the second deadline was missed. He gave no further details.
A prolonged delay could raise opposition doubts about the credibility of the election, said Bjorn Dahlin Van Wees, Africa analyst at the Economist Intelligence Unit.
"It would probably agitate opposition supporters and increase the risk of vote rigging accusations being leveled against the election authorities and the ruling party," he said.
A tight result is widely expected as President Edgar Lungu fends off a challenge from Hakainde Hichilema, who accuses Lungu of mismanaging the economy of the major copper producer that has sought IMF support after being hit by weak commodity prices.
Lungu narrowly won a vote 20 months ago to fill the vacancy created by the death of president Michael Sata. If he fails to win an outright majority this time, he will be forced into a second-round rerun against Hichilema that must be held within 37 days.
During the election campaign, supporters of Lungu's governing Patriotic Front clashed with those of Hichilema's United Party for National Development, but there were no reports of violence on election day.
"It is the possibility of a second round and another four or five weeks of campaigning that raises additional fears of conflict," NKC Africa analyst Gary van Staden said.
"But ... given that Zambia does have strong democratic institutions, that it has a strong and robust civil society and a people with a long history of peaceful engagement, there is reason to remain optimistic."
James Bulaya, a 40-year-old mechanic who voted for Lungu, said: "I think the electoral commission is just trying to do a good job. Obviously this (delay) is raising a lot of anxiety but I am still confident that Edgar Lungu will win."
Susan Jere, a 22-year-old student who supports Hichilema, said: "They can delay the announcement but it won't change the outcome. Ultimately 'HH' will be declared the winner."
Officials reported a high turnout on Thursday, when Zambians also voted for the vice president, members of parliament, councillors and in a referendum on changes to the constitution.
(Editing by James Macharia and Andrew Roche)