Russia may be playing a behind-the-scenes role in escalating tensions in eastern Ukraine, a German government spokeswoman said on Monday, April 14, according to Reuters.

Tensions between the two countries heated up over the weekend, with Kiev saying it planned to launch a "full-scale anti-terrorist operation" against local rebellions in eastern Ukraine that it says are inspired and directed by the Kremlin.

"There are a lot of signs that armed groups in eastern Ukraine are getting support from Russia," Christiane Wirtz, a spokeswoman for the German government, said in Berlin.

"If you look at the appearance, the uniform and the weapons of some of these groups, they can hardly be civilians who have spontaneously formed self-defense groups."

Wirtz did not say whether this meant that the threshold for tougher "third-phase" economic sanctions against Russia had been reached. She said European Union foreign ministers meeting in Luxembourg on Monday would discuss that.

For his part, British Foreign Secretary William Hague said on Monday Russia was clearly instigating the destabilization of eastern Ukraine.

Wirtz said Russia had a special responsibility to prevent further escalation in its fellow former Soviet republic and added that this should include withdrawing Russian troops from the border with Ukraine, reducing natural gas prices for its neighbor and using "restrained language".

"It must also be clear that violence is not a means of settling differences," Wirtz said, A planned meeting on Thursday between the foreign ministers of the United States, Ukraine, Russia and the EU foreign policy chief should be the first step towards a political solution, she said.

A spokeswoman for the German foreign ministry said signs of Russian influence came from daily information from the Organization for Security and Cooperation in Europe (OSCE) mission and "numerous sources".