Belarusian police have rounded up dozens of protesters heading home from peaceful demonstrations, rights groups said on Wednesday, after days in which the authorities exercised comparative restraint towards mass anti-government rallies.

The country’s most celebrated writer, Nobel Prize-winner Svetlana Alexievich, was expected to appear for questioning later on Wednesday in a criminal investigation into an opposition council, two of whose leaders were jailed this week.

President Alexander Lukashenko has faced more than two weeks of mass demonstrations against his 26-year rule since an election which his opponents say was rigged. He denies electoral fraud and says the protests are funded from abroad.

Although Lukashenko has called the protesters “rats” and said he has given the order to clear them from the streets, police had been comparatively restrained in recent days, apparently wary of a crackdown that would add to public anger.

But rights group Spring listed more than 30 people it said had been arrested on Tuesday, mostly in peaceful circumstances.

In one typical account, a man wearing a red-and-white opposition flag on his shoulder was walking with his wife and young son, when an unmarked car pulled up, the group said. Two men in plain clothes jumped out, pushed the woman and child away, shoved the man into the car and drove off.

The Interior Ministry said police had detained 51 people for administrative violations after unsanctioned rallies on Tuesday. It typically reports dozens of such arrests per day.

Alexievich, who won the 2015 Nobel Prize in Literature for work that includes oral histories of World War Two and the Chernobyl nuclear disaster, is one of dozens of high profile figures who formed a new opposition Coordination Council last week.

She was due for questioning in the afternoon at the Investigative Committee, a body handling a criminal investigation into the opposition council for attempting to seize power.

The council says its aim is to negotiate a peaceful transition of authority after the election. Two of its leaders were jailed for 10 days on Tuesday, including the main representative inside Belarus of opposition presidential candidate Sviatlana Tsikhanouskaya. She fled to Lithuania after the election which her supporters say she won.