MOSCOW, April 28. /ITAR-TASS/. Germany's top diplomat has engaged Russian Foreign Minister Sergei Lavrov in talks over the detention of international military observers in south-eastern Ukraine, Russia's Foreign Ministry said on Monday.

Discussion initiated by Germany, according to Russia's Foreign Ministry, brought a review of developments in Ukraine with German Foreign Minister Frank-Walter Steinmeier and "detention of Organization for Security and Cooperation in Europe (OSCE) military observers from several European countries in south-eastern Ukraine,” the ministry said on Monday.

This referred to April 25 events near the eastern Ukrainian city of Sloviansk where federalization supporters are said to have detained a bus carrying unarmed military observers from several OSCE states, reported staying in eastern Ukraine at the invitation of the current Kiev authorities. Russia's Foreign Ministry says Moscow “is taking measures to settle the current situation by all possible means”.Russian diplomatic sources quoting the 2011 Vienna Document on confidence- and trust-building measures say that ensuring inspectors' security "lies fully on the receiving side.”

"It would be logical to expect from current Kiev authorities preliminary coordination of issues of stay, activity and security of inspectors in districts where these authorities do not control the situation and where a military operation against residents of their homeland is under way,” the ministry noted.