The Ukrainian government has accused Russian-backed rebels of using large-caliber weapons despite the ongoing cease-fire in eastern Ukraine.

Fighting in Ukraine's industrial heartland has intensified in the past weeks as peace talks have reached a stalemate. The cease-fire required both sides to withdraw large- and medium-caliber weapons.

The press office of Kiev's operation in the east said in a statement Thursday that the separatists deployed a Grad multiple missile launcher against them in the early hours outside the rebel stronghold of Donetsk. Since the truce was signed in February 2014, there have hardly been any reports of the use of Grads.

The rebel mouthpiece Donetsk News Agency accused government forces of shelling Donetsk suburbs on Thursday morning, killing one fighter, burning down one house and damaging many more.