The Belarus chief prosecutor has launched a criminal case against opposition leaders, accusing them of trying to seize power.
The indictment from Alexander Konyuk says the “creation and activity of the [opposition] Coordination Council are aimed at seizure of state power, and at harming national security”.
Earlier President Alexander Lukashenko ordered police to end the mass protests against him in the capital Minsk.
Long-serving Belarusian leader Alexander Lukashenko won a sixth term with 80.23% of the vote, the central electoral commission said, a result the opposition says was rigged.
Ms Lukashenko’s main challenger, Svetlana Tikhanovskaya, won 9.9%, central electoral commission chief Lidia Yermoshina said.
Tikhanovskaya rejected the results and demanded authorities transfer power to the opposition.
Police in Belarus detained some 7,000 people for taking part in the unauthorized gatherings.
Ms Tikhanovskaya went missing after formally filing a complaint over the election result amid media presence. Nobody could confirm her whereabouts for several hours.
Later, Lithuanian foreign minister, Linas Linkevicius told Lithuanian radio that Ms Tikhanovskaya had been detained for seven hours in Belarus but did not say why or by whom.
Linkevicius said Ms Tikhanovskaya entered Lithuania with her campaign manager, Maria Moroz, who was arrested before the election day.
Rise of Svetlana Tikhanovskaya:
Ms Tikhanovskaya, 37, a former teacher entered the election in place of her jailed husband and went on to lead large opposition rallies.
After her husband was arrested and blocked from registering for the vote, she stepped in to take his place.
The lead-up to poll saw a crackdown on activists and journalists amid the country’s biggest opposition demonstrations in years.
Anger towards Mr Lukashenko’s government has been in part fuelled by the response to coronavirus.
The president has downplayed the outbreak, advising citizens to drink vodka and use saunas to fight the disease. Mr Lukashenko is in power since 1994.
Svetlana Tikhanovskaya’s campaign has said she had been polling 70-80% in some areas.
Tikhanovskaya’s campaign has also claimed the lack of scrutiny, with no observers present during polls has led to rigging of ballots.