Congo's Pool region is a victim of the severe socio-economic crisis, the central African state has faced since 2014 after the closure of the Diamond Cement factory put several hundred Congolese out of work.

The central African state's dependence on oil is one of the issues at stake in the March 21 presidential election.

Current president Denis Sassou Nguesso, who is seeking a new term, has said he is putting agricultural development at the heart of his campaign.

The presidential elections held on Sunday, March 21.

Incumbent Denis Sassou Nguesso aims to extend his decade-long hold on power in the Central African state.

Sassou Nguesso has accumulated 36 years in office -- he was most recently re-elected in 2016, after which the opposition was effectively sidelined and his two main rivals sentenced to 20 years' forced labour. The 77-year-old retired general appears favoured to win a fourth term in Sunday's ballot.

The largest opposition group, the Pan-African Union for Social Democracy, is already boycotting the ballot.

There are however six challengers, including former minister Guy-Brice Parfait Kolelas who was runner-up in 2016.

Sassou Nguesso has placed youth and the development of agriculture at the heart of his campaign, decrying it "shameful" that the country imports most of what it consumes despite its farming resources.

But his pitch to youth seems to have raised a mixed response in a country where most of the population of five million are people aged under 25 who have never known another president.

"Even if there is some hassle here, there's no war like in other countries. Better to stay with Sassou who brings us peace, at least that is good," said Mariela, a 19-year-old high-school student in the coastal city of Pointe-Noire.

"There's no point voting," said Francesc, a 25-year-old law student in the capital Brazzaville. "The dice are loaded in advance."

Oil-dependent

Sitting between Gabon and its giant neighbour the Democratic Republic of Congo, the Republic of Congo has significant oil reserves and 80 per cent of its budget comes from petroleum.

But the former French colony, also known as Congo-Brazzaville, has been hit hard by cycles of falling world crude prices and is also hobbled by corruption and poor infrastructure.

Per-capita GDP in 2012, at the height of an oil boom, peaked at $3,922, but tumbled to $2,279 in 2019, according to World Bank figures.

Last year, the economy contracted by 6.8 per cent, according to the African Development Bank (AfDB). In the 2020 UN Human Development Index, a benchmark of poverty, the country ranked 175 out of 189 countries.

"Sassou has been in power for 37 years. He has no impact. We want some change," said one man waiting for hours for a freight train to travel 18 kilometres (12 miles) in the Pool region, a stronghold of opposition candidate Guy-Brice Parfait Kolelas.

"I am 51 years old. When he came to power I was 10 years old."

Two other Sassou Nguesso rivals, former army general Jean-Marie Michel Mokoko and ex-minister Andre Okombi Salissa, who contested the 2016 vote result, were later sentenced to prison for breaching state security and illegal detention of weapons.

Congo's Catholic Church episcopal conference has already expressed "serious reservations" about the transparency of the ballot and fears a possible internet shutdown on Sunday, as in the 2016 election.

Authorities have refused to accredit election observers from the church.

Took office in 1979

A former elite paratrooper, Sassou Nguesso first ruled from 1979 under a one-party system, stepping down in 1992 when he placed third in multi-party elections.

He then returned to power in 1997 at the end of one of Congo's civil wars. He won votes in 2002 and 2009, although both victories contested by the opposition.

A controversial 2015 referendum removed a 70-year age limit and a ban on presidents serving more than two terms, allowing Sassou Nguesso to run again the following year.

That election sparked protests in Brazzaville and an armed conflict by anti-government rebels in the southern Pool region.