Zambia’s President Hakainde Hichilema has been sworn in for a second five-year term following a disputed election and the arrest of his main opponent on treason charges.

Hichilema – credited with stabilising the economy – swept to victory on 13 August with 60% of the vote, according to official results. Runner-up Brian Mundubile, who received 38%, alleged that the outcome had been tampered with.

He was unable to mount a legal challenge to the result as the courts were sealed off last week on the final day a case could be filed.

Election observers said that while polling day was largely peaceful, some have raised questions about the vote tallying process.

European Union observers said staff in many tallying centres did not record results on tally sheets as soon as they were announced and cited weak verification between digital entries and paper records.

It added that returning officers frequently paused proceedings while awaiting instructions from headquarters.

The day after the poll, security forces raided a property in the capital, Lusaka, linked to Mundubile, killing a former cabinet minister and arresting a number of opposition politicians.

The authorities accused the opposition of planning an armed insurrection, which they denied.

Mundubile and his running mate, Makebi Zulu, had gone into hiding. They were detained by police last week and charged at the weekend.

When Hichilema, 64, came into office in 2021 after a landslide victory, Zambia had recently defaulted on its international debt and had an annual inflation rate of more than 24%.

“We inherited a broken-down country… the economy was declining,” Hichilema told the BBC in Lusaka before the election.

The former businessman negotiated a restructuring of the debt and rebuilt relations with foreign creditors. Inflation has also come down, but prices are still rising and many continue to struggle with the cost of living.

Hichilema now wants to build on the foundations he said he laid over the past five years.

He was sworn into office on Tuesday amid jubilant scenes, as thousands of supporters gathered to celebrate the inauguration.

Presidents from Kenya, Botswana, Zimbabwe, Namibia and Tanzania are among several African leaders attending the inauguration ceremony at the National Heroes Stadium in the capital.

Hichilema was sworn in alongside his running mate, Mutale Nalumango.