Belarusian Nobel Prize-winning author and key opposition figure Svetlana Alexievich has left the country for treatment in Germany, her aide says.
She says the trip is not linked to politics and Ms Alexievich will return.
police held scores of people at the latest rally against President Alexander Lukashenko, following last month’s disputed election.
Separately, French President Emmanuel Macron is to meet opposition figurehead Svetlana Tikhanovskaya on Tuesday.
Mr Macron is beginning a two-day trip to Lithuania, where Ms Tikhanovskaya took refuge after the disputed 9 August presidential election, which she says she won.
Why did Alexievich leave?
She was also the last leading member of the opposition Co-ordination Council still in Belarus who had not been detained.
Speaking to Reuters, her aide, Tatiana Tyurina, said Ms Alexievich had left the country for treatment and also work reasons.
“She will return,” the aide said.
Ms Tyurina said the writer would take part in a book fair in Sweden and an award ceremony in Sicily.
“Of course, the return will also depend on whether the authorities will allow her to return,” Ms Tyurina added.
What are the protests about?
The mass rally held on Sunday was the 50th day of protest over the election.
But the opposition says he cheated and that it won the election with at least 60% of the vote.
Several EU countries and the US say they do not recognise Mr Lukashenko as the legitimate president.