YEREVAN -- Tens of thousands of Armenian antigovernment demonstrators have defied a police warning and gathered on Yerevan's central Republic Square after officers detained protest leader Nikol Pashinian.
Pashinian was detained during a demonstration in the Armenian capital, shortly after failed talks between him and Prime Minister Serzh Sarkisian.
Two other lawmakers were detained along with more than 230 demonstrators following 10 days of mass rallies against an alleged power grab by Sarkisian. The three lawmakers' current whereabouts are unclear.
Pashinian was confronted by masked police officers and other security personnel as he led a crowd of several hundred supporters marching to the city's southern Erebuni district. The police fired stun grenades to stop the march.
Police later tried to disperse crowds gathered in various parts of Yerevan and there were clashes reported between officers and some protesters.
WATCH: Security forces disperse protesters in Yerevan, and detain several participants including Nikol Pashinian and Sasun Mikaelyan
Police said they detained 232 protesters by 5:30 p.m. local time(1330 GMT/UTC).
The Health Ministry said seven people were taken to hospital for problems related to the demonstrations.
More protesters were detained in the evening on the central Republic Square.
WATCH: Armenian security forces in Yerevan detained dozens of protesters who gathered on the city's central Republic Square on April 22.
The Interior Ministry said in a statement that it made the decision to "disperse demonstrators," adding that police were "entitled to carry out arrests and use force."
The Prosecutor-General's Office earlier said that Parshinian and two other detained opposition lawmakers, Sasun Mikaelian and Ararat Mirzoian, will be held for 72 hours.
It said in a statement that the three organized unsanctioned rallies and urged supporters to block streets and entrances to state buildings. It claimed that participants of those gatherings assaulted police officers.
The statement did not say whether there will be criminal charges against the three lawmakers, who are protected by parliamentary immunity. Their prosecution would require parliament to remove their parliamentary immunity.
Meanwhile, thousands of Parshinian's supporters marched in the capital chanting his name. The march was led by four priests in clerical outfits.
Earlier, Sarkisian walked out a meeting with Pashinian after accusing the opposition of "blackmail."
"I came here to discuss your resignation," Pashinian told the prime minister as the meeting began in Yerevan's Marriott Hotel.
"This is not a dialogue, this is blackmail," Sarkisian said before walking out of the meeting room where members of the media were present. The meeting lasted only three minutes, reporters said.
Before walking out, Sarkisian called on Pashinian, whose political alliance, he said, had "only six or seven percent of the vote" in parliamentary elections, not to speak on behalf of the people and not to issue ultimatums to the government.
Pashinian claimed Sarkisian had lost touch with reality and urged his supporters to turn out in larger numbers for peaceful civil-disobedience protests across the country.
He insisted that as long as the protests were peaceful the police should not break them up.
WATCH: LIVE broadcast of RFE/RL's Armenian Service from Yerevan
Sarkisian had said on April 21 that he sought a "political dialogue" with the protest leader..
"I am deeply concerned about the inner-political developments. In order to avoid irreparable losses, I urge Nikol Pashinian to sit at the political dialogue and negotiations table. It should be done immediately," he said in a statement posted on his website.
Serzh Sarkisian was named prime minister after his 10-year stint as president ended two weeks ago.
Opponents says the shift effectively makes Serzh Sarkisian a leader for life. In a 2015 referendum, backed by Serzh Sarkisian, Armenia transitioned to a new system of government that reduces the presidency's power and bolsters the prime minister's role.
Hundreds have been detained in Yerevan in recent days as police seek to stop opposition supporters from blocking streets and paralyzing the capital.
Protesters also rallied in Armenia's second-largest city, Gyumri and in Vanadzor, the third-largest city in the country of about 3 million people. Several protesters were detained in Vanadzor on April 21.
Armenian authorities have repeatedly warned journalists to stay "at a reasonable distance" from the sites where police are "carrying out their lawful actions."
In a statement on April 22, the U.S. Embassy in Armenia urged police and protesters to "avoid violence" and to "prevent an escalation of tensions."
"We are concerned over reports of violence against journalists and demonstrators; we emphasize the need for those responsible for violence against police or demonstrators to be held accountable under the law," it added.
And in a statement on April 22, European Union foreign-policy chief Federica Mogherini's spokeswoman said the EU expected the Armenian authorities to "fully respect this right and to apply the law in a fair and proportionate manner."
"All those who have been detained while exercising their fundamental right of assembly in accordance with the law must be released immediately," Maja Kocijancic added.
She also urged all parties involved to "show restraint and act responsibly," adding that an "inclusive dialogue" aimed at a peaceful resolution of the current situation was "essential."
The OSCE's Office for Democratic Institutions and Human Rights (ODIHR) urged the Armenian authorities to protect and ensure the right to freedom of peaceful assembly in the country.
Serzh Sarkisian stepped down as president when Armen Sarkisian -- his handpicked successor -- was sworn in on April 9 after being elected by parliament. On April 17, parliament elected Serzh Sarkisian as prime minister -- a post that is more powerful than the presidency following the referendum.