Republic of Congo pressed ahead on Sunday with an election in which President Denis Sassou N’Guesso is widely expected to extend his 36 years in power, while the leading opposition candidate remained in hospital with Covid-19.

The watchdog group NetBlocks reported an internet blackout that began in the Central African country around midnight on election day.

After casting his ballot, Sassou N’Guesso said the government was aware of opposition candidate Guy Brice Parfait Kolelas’ illness and had taken the steps necessary for him to be transferred to France for further treatment.

Aides confirmed the medical evacuation flight bringing Mr Kolelas to a French hospital took off from Brazzaville on Sunday afternoon.

Elira Dokekias, who heads the Central African nation’s Covid-19 response, said that Mr Kolelas had been in serious condition on Saturday evening, but that he was stable enough on Sunday to be transferred to a coronavirus unit at the university hospital before his medical evacuation abroad.

Mr Kolelas, 61, had skipped his final campaign event on Friday after telling some reporters a day earlier that he feared he had malaria.

A video circulating on social media on Saturday showed Mr Kolelas wearing an oxygen mask and with a blood pressure cuff on his arm as he lay in a hospital bed.

“My dear compatriots, I am in trouble. I am fighting death,” the candidate says in a weak-sounding voice after removing his oxygen mask.

“However, I ask you to stand up and vote for change. I would not have fought for nothing.”

Mr Kolelas placed second to the incumbent leader in the country’s 2016 presidential election with about 15% of the vote.

Denis Sassou N’Guesso is the third-longest serving president in Africa, ruling from 1979-1992 and then again since 1997.

Republic of Congo has had fewer than 10,000 confirmed cases of Covid-19 since the pandemic began, with 134 confirmed deaths.