Anti-government protesters have forced Armenian Prime Minister Nikol Pashinian to cut short a visit to the southeastern province of Syunik, amid mounting anger over last month's cease-fire deal with Azerbaijan.

Hundreds of protesters on December 21 blocked a section of the main regional highway near the town of Goris, after Armenian forces handed over areas they previously controlled southwest of the breakaway region of Nagorno-Karabakh to Azerbaijan.

Earlier, riot police units sent from Yerevan managed to stop a convoy of demonstrators just outside Goris. Some protesters briefly clashed with police officers.

Addressing supporters in the town of Sisian, Pashinian condemned the blockade as a “provocation” and announced he would not travel to Goris, Kapan, and other towns in Syunik Province.

“We will not resort to the use of force especially during this mourning period,” he wrote on Facebook. “We are returning to Yerevan.”

Goris Mayor Arush Arushanian was detained overnight after urging supporters to prevent Pashinian from entering the mountainous region bordering Iran.

“This is not a political orientation or a partisan initiative. This is a fight for the dignity, security, and physical existence of the people of Syunik,” he wrote on Facebook late on December 21.

The call came after Armenian army units and ethnic Armenian forces last week handed over parts of the Zangelan (known as Zangilan in Azeri) and Kubatli (Qubadli) districts bordering Syunik Province under a Russia-brokered cease-fire deal that took effect on November 10, putting an end to six weeks of fighting with Azerbaijan in and around Nagorno-Karabakh.

Most of Zangelan and Kubatli were recaptured by Azerbaijani forces during the war.

Residents in many communities in Syunik now say they can no longer feel safe because of the proximity of Azerbaijani forces.

They have also raised concerns over the safety of a road connecting Kapan to Goris, with some of its sections passing through disputed areas.

Armenia’s Defense Ministry and National Security Service (NSS) has insisted that Russian border guards will keep the road open for traffic and guarantee its security.

Pashinian, who swept to power amid nationwide protests in 2018, has come under fire since agreeing to the truce, under which some parts of Nagorno-Karabakh and seven districts around it were placed under Azerbaijani administration after almost 30 years of control by Armenians. Nearly 2,000 Russian peacekeepers were also deployed to the conflict zone to monitor the agreement and facilitate the return of refugees.

Thousands of opposition supporters have taken to the streets of Yerevan and other Armenian cities demanding the prime minister resign over what they say was his disastrous handling of the conflict.

Nagorno-Karabakh is internationally recognized as part of Azerbaijan, but the ethnic Armenians who make up most of the region's population reject Azerbaijani rule.

They had been governing their own affairs, with support from Armenia, since Azerbaijan's troops and Azeri civilians were pushed out of the region and seven adjacent districts in a war that ended in a cease-fire in 1994.