Violence mars campaign period
President Lungu faces stiff challenge from businessman Hichilema
Results could be close, forcing a re-run
Zambians have started voting in presidential and parliamentary elections after a campaign marred by violence between rival groups.
Al Jazeera's Tania Page, reporting from a polling station in the capital, Lusaka, said there were queues of hundreds of people waiting to cast their ballots from early on Thursday morning.
There's a lot at stake and the country needs law and order for the economy to stabilise. The cost of living has soared and thousands of people have been laid off in the mining industry.
This is also a historic vote because for the first time it isn't enough that a presidential candidate gets a simple majority, they need to get more than 50 percent.
It's also the first time that candidates have had running mates. This is really to avoid extra elections because in the last decade two presidents have died in office and because they didn't have running mates - elected vice presidents - they've had to hold extra elections. This is the fifth election Zambia has held in a decade.
"Zambians have heeded the call of campaigners to come out and vote in their numbers," she said. "But the opposition has grave concerns that the build-up to the election and possibly the vote itself will not be free and fair."
Hakainde Hichilema, the leader of the opposition United Party for National Development (UPND) told Al Jazeera that the ruling Patriotic Front (PF) was trying to restrict the activities of its opponents.
"We demand a free, fair, transparent and credible election," Hichilema said.
"Let the people of Zambia choose the leadership they want. We will do everything to maintain peace. We want our voters to turn out in large numbers and not fear being beaten by PF thugs out there."
Zambia has seen a wave of pre-election violence in recent weeks, with fighting erupting between opposition and government supporters. Police have also broken up opposition campaigning.
According to the Zambian Elections Information Centre (ZEIC), at least three people have been killed and many injured during campaigning.
"Escalating levels of violence may have a negative impact on the elections and reduce voter turnout," the ZEIC said in a pre-election report on Wednesday.
About 6.7 million people are registered to vote in the southern African country, where President Edgar Lungu's left-leaning PF faces a tough challenge from pro-business opposition leader Hichilema and his UPND.
Lungu, 59, became president after narrowly-winning a January 2015 by-election after the death of his predecessor Michael Sata.
READ MORE: Zambia's voices on the elections and their future hopes
The opposition has accused the PF of not being able to contain a crisis created by falling prices of copper - the country's main revenue earner - and drought-induced electricity shortages, which triggered a steep fall of the kwacha currency and spiralling inflation.
Both said they were confident of outright victory, but either party could fail to garner more than half of the vote as required by electoral law, which would trigger a second round of voting.
The opposition has said Lungu cannot win the elections without resorting to fraud. The president has threatened to mobilise the army if the opposition rejects the results of the vote.
Source: Al Jazeera and agencies