Officials in Ukraine say that Russia-backed rebels in the eastern part of the country violated a fragile cease-fire agreement and used heavy mortar launchers to fire on Ukrainian forces.

The fighting in eastern Ukraine comes after the German and French foreign ministers visited Kiev and appealed to Ukraine's leaders to push ahead with reforms needed to fulfill the Minsk peace agreements and stabilize the fraying situation in the east.

The Ukrainian military press office said in a Wednesday Facebook post that rebel groups fired 84 times on Ukrainian forces in a 24-hour period using 120-mm and 82-mm rocket launchers in violation of peace agreements.

More than 9,000 people have been killed in the conflict since fighting broke out in April 2014 in Ukraine's eastern Donetsk and Lugansk regions.