Tanzania's main opposition party rejected President Samia Suluhu Hassan's landslide victory in elections that triggered deadly protests across the East African nation over the exclusion of her key challengers from the fray.

The main opposition party, CHADEMA, which was barred from the election for refusing to sign a code of conduct and whose leader, Tundu Lissu, was arrested for treason in April, said late on Saturday that the results were "completely fabricated".

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It added, "CHADEMA strongly rejects the so-called election results announced by the National Electoral Commission. These results have no basis in reality, as the truth is that no genuine election took place in Tanzania," it said on X.

"The countrywide demonstrations are clear proof that citizens did not take part in what is being called an election, and that they reject anyone emerging from this flawed electoral process," the party added in the statement on its account.

There was no immediate reaction from the government to CHADEMA's statement. Some demonstrators tore down banners of Hassan and set government buildings ablaze while police fired tear gas and gunshots, according to witnesses of the protests that erupted during Wednesday's vote for president and parliament.

OPPOSITION SAYS HUNDREDS KILLED

CHADEMA said on Friday that hundreds were killed in the protests, while the U.N. human rights office said credible reports indicated at least 10 deaths in three cities.

Demonstrators are angry about the electoral commission's exclusion of Hassan's two biggest challengers from the race and what human rights groups have said are widespread arrests and abductions of opponents.

The government dismissed the opposition's death toll as "hugely exaggerated" and has rejected criticism of its human rights record. Reuters could not independently verify casualty figures.

In a speech from the administrative capital, Dodoma, after being certified as the winner, Hassan said the actions of the protesters were "neither responsible nor patriotic"."When it comes to the security of Tanzania, there is no debate - we must use all available security avenues to ensure the country remains safe," she said.

The authorities have imposed a nationwide curfew since Wednesday and curbed internet access.

Many international flights have been cancelled, and operations have been disrupted at Dar es Salaam's port, a hub for fuel imports and exports of metals mined across the region.