According to reports, the police used light and noise grenades.
Special police units took away deputies of the Armenian parliament N.Pashinyan, Sasun Mikaelyan and Ararat Mirzoyan. All of them represent the opposition faction "Elk" in the Armenian parliament.
Right now, demonstrators and police are negotiating, while the former have demanded that the deputies be released.
The police has sent units to Republic Square in Yerevan, where protesters have flocked, a Sputnik correspondent reports.
On-site special forces are on duty. It is reported that clergymen stood in between the protesters and the police several times during the opposition's march. They asked people to avoid violence.
Some demonstrators called on their supporters to gather in Republic Square in the center of Yerevan.
At the same time, First Deputy Prime Minister of Armenia Karen Karapetyan urged Armenian citizens to be vigilant.
Earlier, Sargsyan stated that he had no desire to apply coercive measures on protesters. The law enforcement agencies remain self-restraining and would not like "the proportionality of the forms of protests to be disrupted, so that the police were forced to use force," he said.
Since April 13, the Armenian capital has been hit by a series of protests against Sargsyan's candidacy for premiership.