Zimbabwe President Emmerson Mnangagwa vowed Tuesday to investigate security forces over their brutal crackdown on protesters, as he scrambled to fend off international criticism and restore order on his return to the country.
The crackdown has underlined fears of a return to the violent repression of Robert Mugabe, who was ousted from power by the military 14 months ago.
"Violence or misconduct by our security forces is unacceptable and a betrayal of the new Zimbabwe," Mnangagwa said on Twitter.
"Chaos and insubordination will not be tolerated. Misconduct will be investigated. If required, heads will roll."
He also sharply criticised the protests last week that were marked by rioting and looting.
"Everyone has the right to protest, but this was not a peaceful protest. Wanton violence and cynical destruction," he said. "This is not the Zimbabwean way."
Mnangagwa issued his statement after landing back in Harare, having cut short a foreign tour seeking much-needed investment.
The protests, which were sparked by the government's more than doubling of fuel prices, were met with a ruthless response from the army and police.
At least 12 people were killed and 78 treated for gunshot injuries, according to the Zimbabwe Human Rights NGO Forum, which recorded more than 240 incidents of assault and torture. About 700 people have been arrested.
Mnangagwa said raising fuel prices "was not a decision we took lightly. But it was the right thing to do."
"What followed was regrettable and tragic," he added.
Mnangagwa, 76, had visited Russia, Belarus and Azerbaijan and Kazakhstan before cutting short his trip before his planned attendance at the Davos summit of world leaders this week.
He has repeatedly pledged a fresh start for Zimbabwe since he came to power in November 2017 after Mugabe was toppled, ending 37 years in office that were marked by authoritarian rule and economic collapse.
But Zimbabweans have seen little evidence of the promised economic revival or increased political freedoms.
The UN human rights' office criticised the government's reaction to the protests, which were fuelled by daily shortages of banknotes, fuel, food and medicine, as well as mass unemployment.
Accused of conducting a deadly crackdown on dissent, the army and police denied any wrongdoing, saying some assailants raiding homes and beating people were wearing official uniforms to pose as security personnel.
The High Court in Harare ruled Monday that government had no powers to order the shutdown of the internet that was imposed as protests swept across the country.
Handing down judgement in a case brought by human rights lawyers and journalists, Judge Owen Tagu said "it has become very clear that the minister had no authority to make that directive".
Internet and social media appeared to be partially returning to normal on Tuesday morning.
Mugabe, now 94, ruled Zimbabwe with an iron fist from independence from Britain in 1980 until November 2017.
The military, fearing that Mugabe's wife Grace was being lined up to succeed him, seized control and forced him to resign before ushering Mnangagwa to power.