Armenian police detained 88 people at a protest in the capital Yerevan by demonstrators demanding the resignation of Prime Minister Nikol Pashinyan over his decision to cede several border villages to Azerbaijan.
Armenia said last month it would return the uninhabited villages in what both sides said was an important milestone as they edge towards a peace deal after fighting two wars since the collapse of the Soviet Union.
The decision has angered many in Armenia. Protesters led by a senior Armenian cleric reached Yerevan on Thursday after walking for several days from a village in the country's northeast, a distance of some 100 miles (160 km).
Archbishop Bagrat Galstanyan called for Prime Minister Pashinyan's resignation at rally of thousands of supporters, who he encouraged to begin acts of civil disobedience aimed at toppling the government.
Opposition parties in Armenia's parliament have said they will try to begin impeachment proceedings against Pashinyan, whose Civil Contract party retains a majority of lawmakers, and is unlikely to break with him.
Armenia is a treaty ally of Russia and traditionally Moscow's closest partner in the South Caucasus, but bilateral relations have sharply deteriorated in recent months as Yerevan has sought to build ties with the West, blaming Russia for failing to defend it from Azerbaijan.
US press secretary Karoline Leavitt has stated that reports that the White House has requested a ceasefire in the Iran war are wrong in a brief on Wednesday, but added that discussions about a second round of talks with the Iranians were ongoing and productive.
Prime Minister Benjamin Netanyahu has said on Wednesday the Israeli military continued to strike at Hezbollah and was about to overcome what he described as the militia's stronghold of Bint Jbeil, as pressure mounted for a ceasefire between Israel and Lebanon.
The United States and Iran made progress in talks on Tuesday and are moving closer to a framework agreement to end the war, Axios reported on Wednesday, citing two US officials.
Russian forces attacked the Ukrainian capital Kyiv and other cities early on Thursday, killing three people, including a 12-year-old child, injuring more than 20 and badly damaging buildings, officials said.
A fire at the largest of Australia's two oil refineries has hit petrol production, authorities said on Thursday, just as the nation faces pressure to shore up fuel security with the Iran war disrupting global supply.