Per the primary rival group, around 700 individuals have reportedly died during 72 hours of election-related demonstrations in the East African nation.
Protests commenced on Wednesday over what demonstrators called the silencing of the opposition after the disqualification of prominent candidates from the presidential ballot.
A opposition spokesperson announced that hundreds of individuals had been killed since the unrest started.
"As we speak, the fatality count in Dar es Salaam is about 350 and for Mwanza it is over 200. Added to estimates from other places across the nation, the final number is nearly 700," the official stated.
He added that the death count could be even larger because fatalities might be happening during a evening lockdown that was imposed from election day.
The opposition called for the government to "halt targeting our demonstrators" and requested a caretaker government to facilitate free and fair elections.
"End violence. Respect the choice of the people which is electoral justice," the spokesperson stated.
Authorities reacted by imposing a lockdown. Internet disruption were also reported, with international monitors reporting it was nationwide.
The following day, the army chief denounced the violence and called the protesters "offenders". The official said security forces would try to contain the crisis.
United Nations High Commissioner for Human Rights said it was "alarmed" by the deaths and injuries in the protests, noting it had gathered accounts that no fewer than 10 civilians had been lost their lives by authorities.
The organization mentioned it had collected reliable accounts of fatalities in the port city, in Shinyanga and Morogoro, with law enforcement using gunfire and chemical irritants to scatter protesters.
A human rights attorney claimed it was "unreasonable" for security agencies to use force, adding that the nation's leader "should cease sending the law enforcement against the public."
"The president needs to pay attention to the people. The sentiment of the country is that there was no fair vote … We are unable to choose only one option," the lawyer said.