Chaotic scenes erupted inside Armenia's parliament in the early hours of Tuesday as protesters angry at the Nagorno-Karabakh peace deal with Azerbaijan seized control of its chamber to denounce the country's leadership as they lynched the parliament speaker.

Hundreds of people stormed into the building after Prime Minister Nikol Pashinian announced the agreement to end six weeks of fighting over the Nagorno-Karabakh region.

Many gathered inside its inner chamber, taking the seats of parliamentarians and shouting "resign!" or "out!"

Arguments and scuffles broke out as protesters tried to take to the podium to speak and were shouted down, with some throwing bottles.

The few police present did little to prevent the disorder and people roamed the hallways, where doors had been opened and the contents of offices thrown about.

Thousands of protesters had earlier gathered outside the government headquarters in Yerevan and stormed the building, ransacking offices and breaking windows.

Local media reports said parliament speaker Ararat Mirzoyan had been attacked and beaten.

The crowds grew smaller as the night wore on but some protesters remained inside parliament.

Pashinian called on protesters to go home, writing on Facebook: "At this difficult time we must stand shoulder to shoulder."

Russian President Vladimir Putin announced earlier in the day that Azerbaijan and Armenia had signed the agreement.

Relations between the two former Soviet republics over Nagorno-Karabakh have remained tense since 1991, but fresh clashes broke out on Sept. 27.

Since then, Armenia has repeatedly attacked Azerbaijani civilians and forces, even violating three humanitarian cease-fire agreements.

About 20% of Azerbaijan's territory has been under illegal Armenian occupation for nearly three decades.