The country's largest telecoms company Econet confirmed that the government has ordered suspension of the internet across all networks following protests over a government decision to more than double petrol prices.
Zimbabwe's government has again forced a "total internet shutdown," a media group says, after a days-long violent crackdown on people protesting dramatic fuel price increases.
MISA-Zimbabwe shared a text message from the country's largest telecom company, Econet, calling the government order "beyond our reasonable control."
The shutdown faces a court challenge from the group and Zimbabwe Lawyers for Human Rights.
Soldiers were still controlling long fuel lines in the capital Harare on Friday, and many wary residents stayed at home. Some said they can no longer afford fares for public transport.
A prominent pastor and activist who faces a possible 20 years in prison on a subversion charge is set to appear in court on Friday. Evan Mawarire was one of more than 600 people arrested this week.
Mawarire said it was "heartbreaking" to see the new government of President Emmerson Mnangagwa acting like that of former leader Robert Mugabe. The pastor is accused of inciting civil disobedience online.
"Our country is going through one of the most trying periods in its history," the Zimbabwe Catholic Bishops' Conference said in a sweeping statement lamenting the government's "intolerant handling of dissent" and its failure to halt economic collapse.
International calls for restraint by Zimbabwe's security forces are growing, while Mnangagwa prepares to plead for more investment at the World Economic Forum in Davos, Switzerland.
He announced the fuel price increase on the eve of his overseas trip, leaving hardline former military commander and Vice President Constantino Chiwenga as acting president.
Nationwide protests over rising fuel prices
Gasoline in the economically shattered country is now the world's most expensive.
Zimbabweans heeded a nationwide stay-at-home call from opposition groups earlier this week in protest.
Rights groups and others have accused security forces of targeting activists and labor leaders in response, with the United States expressing alarm.
UN alarmed over 'excessive force'
The United Nations on Friday called on Zimbabwe to halt its crackdown on anti-government protesters, voicing alarm about security forces' "excessive use of force", including firing with live ammunition.
"We are deeply troubled by the socioeconomic crisis that is unfolding in Zimbabwe and the repression of large scale protests in the country," Ravina Shamdasani, spokeswoman for the UN human rights office, told reporters in Geneva.
"We call on the government to find ways of engaging with the population about their legitimate grievances and to stop the crackdown against protesters," she said.
'Assaults with sharp objects'
The Zimbabwe Association of Doctors for Human Rights has said it had treated 68 cases of gunshot wounds and 100-plus other cases of "assaults with sharp objects, booted feet, baton sticks" and more.
Hungry residents of the capital, Harare, who ventured out seeking food reported being tear-gassed by police.
Death tolls have varied. Eight people were killed when police and military fired on crowds, Amnesty International said.
Zimbabwe's government said three people were killed, including a policeman stoned to death by an angry crowd.
The demonstrations amount to "terrorism," Information Minister Monica Mutsvangwa said, blaming the opposition.
State Security Minister Owen Ncube thanked security forces for "standing firm."
Zimbabweans had briefly rejoiced when Mnangagwa succeeded Mugabe, who was forced out in late 2017, thinking the new president would deliver on his refrain that the country "is open for business."
But frustration has risen over the lack of improvement in the collapsed economy, which doesn't even have a currency of its own.*
The UK's minister for Africa, Harriett Baldwin, has summoned Zimbabwe's ambassador to discuss "disturbing reports of use of live ammunition, intimidation and excessive force" against protesters.
The European Union in a statement late on Thursday noted the "disproportionate use of force by security personnel" and urged that internet service be restored.
* Zimbabwe scrapped its currency, the Zimbabwe dollar, a decade ago, and adopted a basket of foreign units of which the US dollar is the most widely used. [Bloomberg]