Armenia said at least 49 of its soldiers were killed; Azerbaijan said it lost 50.

The fighting erupted minutes after midnight with Azerbaijani forces unleashing an artillery barrage and drone attacks in many sections of Armenian territory, according to Armenia’s Defense Ministry.

The ministry said fighting continued during the day despite Russia’s attempt to broker a quick cease-fire. Shelling grew less intense but Azerbaijani troops still were trying to advance into Armenian territory, it said.

It added that the Azerbaijani shelling damaged civilian infrastructure and wounded an unspecified number of people.

Azerbaijan’s Foreign Ministry said it was responding to a “large-scale provocation” by Armenia late Monday and early Tuesday. It said Armenian troops planted mines and fired on Azerbaijani military positions.