Tanzanian authorities faced mounting concern over killings during and after last week's election, with the largest opposition party charging on Tuesday that the security forces were secretly dumping the bodies of hundreds killed in the violence that shocked the region.

Protests spread across the East African country in the aftermath of voting on Wednesday, continuing for several days as young people came into the streets of Dar es Salaam, the commercial capital, and elsewhere to protest what they felt was not a free or fair election.

Security agencies cracked down on protesters by firing live bullets and tear gas canisters, and a nationwide curfew was declared.

President Samia Suluhu Hassan was declared the winner with more than 97% of the vote, a rare landslide victory in the region, despite the low turnout reported by foreign observers.

It was her first election victory — she rose to the presidency automatically as vice president in 2021 after the sudden death of her predecessor, John Pombe Magufuli.

Hassan's controversial win has only intensified criticism of the election as not credible.

Her main rivals — Tundu Lissu of Chadema and Luhaga Mpina of ACT-Wazalendo — had been prevented from running for the presidency.

Lissu has been jailed for several months, facing treason allegations stemming from his call for electoral reforms. His deputy, John Heche, was also detained days before voting.

Chadema official Deogratius Munishi, said the party would not enter into any political pact with the government until there are electoral and judicial reforms to ensure justice is served.

“We want to see those who shot Tanzanians being held accountable,” he said.

Human Rights Watch on Tuesday condemned the violent crackdown on protesters in a statement that urged Tanzanian authorities to “end the use of excessive and lethal force against protests, and take steps to ensure accountability" by security forces.

The group cited point-blank shootings reported by various residents.

Tanzanian authorities have not responded to Chadema's claim of more than 1,000 deaths.

Others, including the U.K., Norway and Canada, have cited what they said were credible reports of a large number of fatalities.

And the Catholic Church says people died in their “hundreds,” although it was also unable to verify or confirm the exact numbers.

Hassan, Tanzania's first female leader, was inaugurated on Monday. She acknowledged in her speech that there had been loss of life and urged security agencies to ensure a return to normalcy.