Malawi's former President Peter Mutharika has taken a comfortable lead in the country's presidential race, with two-thirds of districts having reported provisional results.

The 85-year old has received around 66% of the valid votes counted so far, with his closest rival, the incumbent Lazarus Chakwera, 70, trailing on around 24%.

Results declared so far indicate that Mutharika has won in areas known to be Chakwera strongholds, including the capital, Lilongwe, and Nkhotakota.

But Chakwera's camp has not given up, saying that once results are declared from other areas, his vote will increase and he could force a run-off.

A candidate needs more than 50% of the vote to be declared the winner, with Malawians eagerly awaiting the final result from last Tuesday's election.

The Malawi Electoral Commission has until the end of Wednesday to announce it.

At least two of the 12 districts still to declare results have a large number of registered voters, and Chakwera's camp believes he will do well there. These includes rural areas around Lilongwe and Dedza.

Two other districts, where Mutharika is expected to do well, have had their results withheld by the electoral commission as it checks whether they are accurate.

The commission said it was committed to transparency, accuracy and credibility.

It added that it was carefully checking every tally sheet, after the constitutional court annulled Mutharika's victory in 2019 because of irregularities.

Chakwera won the re-run by a wide margin, but during his presidency Malawi's economic crisis has deepened, with high inflation, food and fuel shortages and constant power cuts.

On Friday, Chakwera's party said it had discovered "irregularities" and "serious anomalies", and had asked the electoral commission to conduct a "physical audit" of results. The party did not specify the irregularities.

Police said eight data entry clerks had been arrested on accusations of trying to manipulate results.