YEREVAN, Sep 20 (Aljazeera) - Thousands of protesters have gathered in the Armenian capital to denounce the government’s perceived failure to support Armenian separatists in Nagorno-Karabakh, after the breakaway region was forced into surrender by Azerbaijan.

The protesters gathered on Wednesday at Republic Square, in the heart of Yerevan, demanding the resignation of Prime Minister Nikol Pashinyan, who presided over the defeat to Azerbaijan in a 2020 war and now the final collapse of Karabakh’s Armenian authorities.

Opposition politicians gave speeches from a stage denouncing Pashinyan, who took power in a 2018 revolution during which he addressed rallies on the same square, while some protesters threw bottles and stones at his office and scuffled with police.

“Russia washed its hands in Artsakh, our authorities have renounced Artsakh,” opposition politician Avetik Chalabyan told the crowd, using the Armenian name for Karabakh.

“The enemy is at our doorstep. We must change authorities to change national policy,” he added.

Lawmaker Ishkhan Saghatelyan called on parliamentary opposition forces to launch an impeachment procedure against the prime minister.

Azerbaijan on Wednesday announced it had halted its offensive, which it described as a “counter-terrorism operation”, after Armenian separatist forces in Nagorno-Karabakh agreed to a ceasefire whose terms signalled the area would return to Baku’s control.

Azerbaijan said that it wanted a “smooth reintegration process” for Karabakh’s Armenians and rejected accusations that it wanted to “ethnically cleanse” the region.

Azerbaijan’s President Ilham Aliyev that his nation “restored its sovereignty” by waging an offensive against Armenian-backed separatists on its territory and signalled a possible future peace treaty with Yerevan.

“Illegal Armenian units have begun the process of withdrawal from their positions. They accepted our terms and began surrendering their arms,” Aliyev said in a televised address.

Both sides agreed to hold talks on reintegrating the breakaway territory into the rest of Azerbaijan on Thursday in the city of Yevlakh, Azerbaijan.

Aliyev said the Armenian government had, “surprisingly, showed political competence” by agreeing to the terms of the ceasefire.

“We value this … the developments that took place yesterday and today, will have a positive impact on the peace process between Azerbaijan and Armenia,” he said.

Russia, which has had peacekeeping troops on the ground in Karabakh since the end of the 2020 war, said it hoped for a “peaceful” resolution to the conflict, without mentioning a ceasefire agreement.

“We are in close contact with all the sides of the conflict: with authorities in Yerevan, with [separatist Karabakh] authorities in Stepanakert and in Baku,” President Vladimir Putin said during a meeting with China’s Foreign Minister Wang Yi.

In a statement giving an account of a phone call between Putin and the Armenian prime minister, Pashinyan, the Kremlin said the Russian president had “noted with satisfaction that it was possible to overcome the acute phase of the conflict, and welcomed the agreement … on a complete cessation of hostilities and the holding of negotiations on September 21”.

The Kremlin had already said it considered Baku’s lightning offensive an internal action on its own sovereign territory and had dismissed allegations from Armenia, Moscow’s ally, that Russian peacekeepers had done too little to protect Karabakh’s Armenian population.

Putin said Russian peacekeepers would mediate the upcoming talks between Armenian separatists and Azerbaijan on Thursday.