(AFP) - Southern Africa's diamond-rich nation of Botswana votes in general elections Wednesday, with the ruling party seeking to extend its nearly six-decade rule and hand a second term to President Mokgweetsi Masisi.

More than a million people are registered to vote after polls open at 6:30 am (0430 GMT), with four presidential candidates in the race to head the region's oldest democracy, installed on independence from Britain in 1966 when the Botswana Democratic Party (BDP) took office.

Voters in the arid and sparsely populated country have voiced concerns about an economic slowdown and unemployment that has reached 27 percent, amid claims of government corruption and mismanagement.

But the ruling party has batted away the criticism and points to the impact of the Covid-19 pandemic on the economy, with weakened demand for diamonds also chipping away at revenues.

"In 2019, we had a clean sweep of Gaborone," Masisi, 63, told around 400 cheering supporters at a final late-night rally in the capital late Tuesday. "This year, I want to polish," the eloquent US-educated former school teacher said.

Dressed entirely in the red colours of the BDP, Queen Mosiane, 34, said she was loyal to the party because its government had supported her when she became an orphan, including with education and healthcare that is covered by the state.

"We live peacefully in this country because of BDP," she said. "It's not time to change because we don't know what are we inviting."

"The opportunities that we find, and our kids are going to find in the future, are because of the BDP," said civil servant Refile Kutlwano, 34, at the same rally. "The opposition is not ready to rule."

Masisi was elected in 2019 with around 52 percent of the vote. While the party is not expected to fare much better this time, the opposition is divided.

- Divided opposition -

The main opposition alliance is the left-leaning Umbrella for Democratic Change (UDC), led by human rights lawyer, Duma Boko, 54.

It lost two key members in the run-up to voting day with the Botswana Patriotic Front (BPF) and Botswana Congress Party (BCP) quitting and each fielding their own presidential candidates.

It was a blow to voters like Ookeditse Letshwenyo, 23, who saw the UDC offering opportunities to young people struggling to find jobs that pay beyond the minimum wage of around 1,500 pula ($110 dollars) a month.

"Since our independence we've been ruled by the same people, with the same mindset, with the same goals," said Letshwenyo, who has launched an IT start-up. "You can't win against the BDP while you are divided," he said.

While the surprise return six weeks ago from three years of self-exile of the previous president Ian Khama to campaign against Masisi added some energy to the opposition, analysts said his influence was limited to a few districts.

In the lead-up to voting day, opposition groups made various claims of irregularities by the Independent Electoral Commission (IEC), including failing to share a digital version of the voters roll and a shortage of ballot papers in early voting for security personnel.

Despite some disillusionment around the ruling party, with its "historical momentum and the limping opposition, the BDP’s path to victory appears not only likely but increasingly evident," the independent Mmegi newspaper said.

With 61 seats up for grabs in parliament, Botswana's first-past-the-post system means that the first party to take 31 seats will be declared the winner and install its candidate as president.

Counting will start in the hours after polling stations close at 7:00 pm (1700 GMT) Wednesday with results due late Thursday, IEC spokesperson Osupile Marob said.

© Agence France-Presse