Guinea's junta leader Gen Mamady Doumbouya has taken a huge lead in a presidential election his main challengers were barred from contesting, initial results show.

Gen Doumbouya is hoping to legitimise his rule after seizing power in a coup four years ago.

A civil society group campaigning for the return of civilian rule condemned the election as a "charade", while opposition candidates said the poll was marred by irregularities.

On Monday, internet monitoring organisation NetBlocks reported that access to social media platforms TikTok, YouTube and Facebook had been restricted as Guineans waited for the full results.

There has been no official comment on the restrictions, but opponents see it as an attempt by the junta to stifle criticism of the results.

Gen Doumbouya, 41, won more than 80% of the vote in numerous districts in capital city Conakry, according to official partial results read out on television by Djenabou Toure, head of the General Directorate of Elections.

Gen Doumbouya had a big lead in several other areas as well, including Boffa and Fria in the west, Gaoual in the north-west, northern Koundara and Labe, and Nzerekore in the south-east.

After overthrowing then-83-year-old President Alpha Condé in 2021, he promised not to seek election and to hand power to a civilian.

"Neither I nor any member of this transition will be a candidate for anything... As soldiers, we value our word very much," he said at the time.

Gen Doumbouya broke his promise by putting his name on the ballot after a new constitution, implemented in September, permitted him to run for office. 

Eight other candidates took part in Sunday's election, but with the exclusion of main opposition parties RPG Arc en Ciel and UFDG, none of the participants have a solid political footing. 

Although he is popular with many of Guinea's youth, Gen Doumbouya has been criticised for restricting opposition activities, banning protests and stifling press freedom in the run-up to the elections.

The general justified deposing Condé on similar charges - including rampant corruption, disregard for human rights and economic mismanagement.

Guinea has the world's largest bauxite reserves and some of its richest iron ore. Last month, authorities launched the gigantic Simandou iron-ore mine to widespread anticipation.

However, over half of the population lives in poverty, according to World Bank figures.