Russia's 'blockade' of Sea of Azov port angers Ukraine Huge cranes used to unload cargo ships sit idle on the docks of Ukraine's commercial port of Mariupol on the Sea of Azov. The small sea is located in a zone of heightened tensions between Russia and Ukraine: on the border of the Crimean peninsula annexed by Russia and the Kremlin-backed rebel regions of eastern Ukraine. As tensions escalate, Kiev and the West accuse Russia of deliberately blocking ships from entering Ukraine's port on the sea. IMAGES AND SOUNDBITES