Tens of thousands of Slovaks repeatedly took to the streets amid a political crisis in major protests triggered by the slaying of an investigative reporter and his fiancee earlier this year. They led to the collapse of a coalition government led by Prime Minister Robert Fico.
Police say they had to act after they received an anonymous criminal complaint. The organizers said the complaint suggested they were paid by U.S. philanthropist George Soros, something that Fico repeatedly charged.
President Andrej Kiska on Tuesday called the police questioning intimidation. The organizers denied any wrongdoing and announced more protests for Friday.