Ukraine's opposition is planning new rallies amid concern about military intervention in the country's worst crisis since independence.
The rally, due to be held on Sunday in Independence Square in Kiev, will press for more concessions from the president, Viktor Yanukovich, including the immediate release of protesters and the formation of a new government.
An official statement posted on Sunday said Yanukovich was returning to work on Monday after four days of sick leave.
The Automaidan movement, whose leader Dmytro Bulatov earlier this week said he was abducted and tortured before being released, is planning a car convoy that will head towards the president's mansion.
The planned protests would come a day after a pan-European security conference in Munich, where the Ukraine protest movement gained the backing of the US and EU while Russia, the traditional influence in Ukraine, said such support was "double standards".
East or West?
Yanukovich and his ruling Regions Party have passed a law granting an amnesty to activists arrested in more than two months of protests, sparked by his rejection of a partnership with the EU under Russian pressure in favour of a $15bn bailout and gas supply discounts from Moscow.
Addressing the Munich conference, Vitali Klitschko, a former boxer turned Ukraine opposition leader, said: "I leave the conference stronger because I feel huge support from friends of Ukraine. Everyone is afraid that instability in one of the largest countries in Europe could bring instability to the whole region."
|Kerry meets Ukraine's opposition leaders in Munich
Differences between Russia and the West on Ukraine and Syria, where Russia backs President Bashar al-Assad, made for a chilly atmosphere on the Munich podium.
Kerry and other Western diplomats put the burden of responsibility for the violence in Ukraine on the government.
The opposition also said it was concerned that the Ukraine military would become involved, after a statement from the army called on the president to end the unrest by lawful means.
Wounded activist's case
In another development Leonid Kozhara, the Ukrainian foreign minister, accepted a request by Germany for Bulatov to be allowed to seek treatment in EU member states.
Bulatov was found on Thursday with his face badly beaten and with wounds to his hands, saying he had been tortured by kidnappers who spoke Russian. Two videos were released of his condition, the first showing him covered in blood with a long gash on his cheek, and the second showing him after a day in hospital, obviously dazed with a black eye, cut hands and the wound on his cheek beginning to heal.
In an interview with Al Jazeera, Kozhara dismissed Bulatov's injuries as "a scratch".
"Physically this man is in a good condition. The only thing he has is a scratch on one of his cheeks," Kozhara said.
"It looks like the alleged story that he was kidnapped and tortured is not absolutely true. The investigation is going on."
But Bulatov's lawyer told Al Jazeera that his client was in intensive care unit after surgery.
"He was kidnapped, beaten up and tortured," Ruslan Radetski said. "The doctors haven't said yet when he will be able to leave the hospital, treatment is under way."
Ukraine's Foreign Ministry later issued a statement saying that Kozhara had been misunderstood.
The comments "do not reflect the real attitude of Minister Kozhara on this tragic situation", it said.
"The minister is profoundly sorry for what happened to Dmytro Bulatov and wishes him a speedy recovery."
With additional reporting by Tamila Varshalomidze in Kiev