Zimbabwean President Emmerson Mnangagwa has broken off a trip to Europe after violent protests in his home country.
Mr Mnangagwa had been due to attend the Davos economic summit where he was expected to seek investment for Zimbabwe.
Ministers said the opposition Movement for Democratic Change (MDC) is using sharp fuel price increases as a pretext for violence.
But the MDC accuses the authorities of a brutal crackdown.
Mr Mnangagwa’s announcement of a steep increase in the fuel price over a week ago led to angry protests in the capital, Harare, and the south-western city of Bulawayo.
Rights groups said at least 12 people have been killed but this has not been officially confirmed.
Mr Mnangagwa arrived back in Harare late on Monday night.
“I am happy that the country is quiet. Our people should concentrate on their work,” he said, adding: “We want Zimbabwe developed.”
Earlier, MDC leader Nelson Chamisa said many of the party’s members had been detained including four MPs.
He accused security forces of attacking families in their homes.
The Zimbabwe Congress of Trade Unions, the umbrella group that called the protests, said its leader Japhet Moyo has also been arrested.
As tensions rose, the government said on Sunday that the security forces’ actions were just “a foretaste of things to come”.
“The MDC leadership has been consistently pushing out the message that they will use violent street action to overturn the results of [last year’s] ballot,” presidential spokesman George Charamba said.
The opposition rejected a court ruling in August 2018 that confirmed that President Mnangagwa had defeated Mr Chamisa.
Mr Chamisa told the BBC that there was “no justification whatsoever of having soldiers with live ammunition, with guns, machine guns, AK47 on the streets, beating up citizens”.
“People are being approached in their homes, they are being taken out of their homes with their families even if they are sleeping… a lot of people have been arrested for no apparent reason,” he said.
MDC national chairperson Thabitha Khumalo said that she had gone into hiding after the police and military turned up at her home at night. (BBC)