Zimbabwe police announced Thursday a two-week ban on protests in the capital Harare, after a recent surge of demonstrations against President Robert Mugabe and his government.
Harare police chief Newbert Saunyama said in a statement that his officers' powers "will not be sufficient to prevent public disorder" at public marches and protests.
A ban on protests in Harare would be put in place from Friday until September 16 as a result, he added.
The decision comes as 92-year-old Mugabe, who has been in power since 1980, faces a wave of dissent.
Zimbabwe has witnessed a string of violent protests in recent weeks, with demonstrators calling on the long-serving leader to step down.
He has previously crushed such movements during the course of his authoritarian rule, but speculation has grown over his succession amid increasing signs that he is suffering from ill health. He has nonetheless vowed to stand for reelection.
The opposition had planned more protests on Friday, calling for electoral reforms ahead of the next general election in 2018.
But late Thursday it announced the demonstrations had been postponed although it was not immediately clear if it was a result of the police ban.
Last week police arrested at least 70 people when street protests were held in Harare.
Police used tear gas to halt the demonstration, which had court approval.
On Wednesday, a call for a general strike was largely ignored, with the opposition blaming the poor response on intimidation by security forces which have been deployed in many large towns.
Zimbabwe has suffered an economic crisis since the start of the century.
Ninety percent of the population is not in formal employment.
The cash-strapped government has been slow to pay the salaries of public sector workers.