Separatist rebels and government troops are both reporting violations of a cease-fire that was supposed to begin in eastern Ukraine at midnight on Wednesday.

Rebels on Tuesday declared a unilateral cease-fire, and the visiting German foreign minister said the following day Ukraine had also agreed to observe the truce.

Russian state television on Thursday quoted rebel officials as saying their forces came under mortar fire earlier that day. Ukrainian army spokesman Ivan Arefyev said that fighting subsided at midnight but the rebels used small arms and hand grenades in the morning, the Interfax news agency said.

The foreign ministers of France and Germany, key mediators in the Ukrainian peace process, met with the Ukrainian president on Wednesday and are expected to travel to the east on Thursday.