Armenia on Sunday has shot down two helicopters and three drones of Azerbaijan in the Nagorno-Karabakh region, Prime Minister Nikol Pashinyan said on social media.
The move is a response to Azerbaijan's attack on civilian settlements in the disputed territory, according to Armenian Defense Ministry.
Also on Sunday, Azerbaijan's Defense Ministry said it is currently launching a counter-offensive in the region.
Heavy fighting in the Nagorno-Karabakh region has caused civilian casualties on both sides, the Azerbaijani presidency said.
Armenia and Azerbaijan have been at loggerheads over the mountainous region of Nagorno-Karabakh since 1988.