Armenian opposition protesters calling for the prime minister's resignation have burst into a government building in the capital Yerevan and held a rally there, Russian media report.
Several dozen activists were involved, Interfax news agency said.
Last week PM Nikol Pashinyan warned of an attempted military coup. Opponents blame him for Armenia's defeat by Azerbaijan in a disputed region.
Russia brokered a truce after fighting in Nagorno-Karabakh last year.
An opposition activist in Yerevan said Monday's break-in showed that "we can get into any government building". The building reportedly houses several ministries.
Last week the army said that the prime minister and his cabinet must resign, after he sacked a commander.
The prime minister has faced protests after losing last year's bloody conflict with Azerbaijan over the disputed region of Nagorno-Karabakh.
The enclave is internationally recognised as part of Azerbaijan but had been controlled by ethnic Armenians since a 1994 truce.
During the six weeks of fighting late in 2020, Azerbaijan not only recaptured areas around the enclave but also took the key town of Shusha inside it.
Under the Russian-brokered deal that emerged shortly afterwards, Azerbaijan kept the areas it captured. Hundreds of Russian peacekeepers are deployed in the disputed area.