The leaders of Russia, France and Germany have expressed their concern over a recent uptick in fighting in eastern Ukraine.

Both government forces and Russia-backed separatists have reported heavy shelling of their positions in recent days, and the Ukrainian presidential administration on Friday said two troops had been killed in the past 24 hours.

The Kremlin said Friday Russian President Vladimir Putin, French President Francois Hollande and German Chancellor Angela Merkel spoke on the phone to discuss eastern Ukraine. Moscow said the leaders expressed concern over the recent violations of the cease-fire that the three countries acted as guarantors for last year.

The peace accords signed in Minsk and mediated by the three countries called for a cease-fire, pullback of heavy weaponry as well as political reform.