Armenia’s prime minister Nikol Pashinyan agreed in April to return the four villages in what both countries called an historic step towards striking a peace deal after two wars since the collapse of the Soviet Union.

Pashinyan said at the time: “In this process, the Republic of Armenia receives a reduction in risks associated with border delimitation and security.”

But since then opponents led by Archbishop Bagrat Galstanjan, head of the Tavush diocese on the border with Azerbaijan, have been calling for his resignation.

Taking to the capital Yerevan on Monday, demonstrators trying to block the streets were arrested for what police called "resisting".

They added that 151 had been detained.

Demonstrators also took to the capital last week to demand Pashinyan’s resignation, a suspension to border issue talks, and an end to unilateral concessions to the Azerbaijan capital Baku.

The demonstration was again led by Galstanjan who told his supporters that he would not shy away from his new responsibilities - including taking on the role of candidate for prime minister - as long as parliamentarians were ready to talk about forcing Pashinyan to step down.

Under Armenian law, a no-confidence motion must include the name of the candidate who would replace the incumbent prime minister.

Galstanjan said that he was ready to take up this position “if God allows”, adding : “We need a new government.”

Disputed borders

Changes in relations between Armenia and Azerbaijan began in September last year, when Azerbaijan regained control over the disputed Armenian enclave, Nagorno-Karabakh, as a result of a lightning military offensive.

However, much of the border remains disputed, with both sides occupying villages that once belonged to the other side.

The opposition in Armenia criticized the prime minister for agreeing to hand over the border villages to Azerbaijan without convincing the neighbor to withdraw from parts of Armenian territory occupied during fighting in 2021-22.

Azerbaijan is better armed than Armenia thanks to oil revenues, and also has the support of Turkey.

Much poorer Armenia has since moved closer to Europe, believing that Russia, its traditional ally, has stopped supporting it sufficiently.