MOSCOW (Reuters) - Russian Foreign Minister Sergei Lavrov called for an immediate ceasefire in Nagorno-Karabakh on Sunday and said Moscow was ready to help seek a solution to the conflict via the Organization for Security and Co-operation in Europe. Lavrov also told his Armenian counterpart on Sunday that Russia was concerned about the rising tally of casualties from the war that broke out in late September, the Russian foreign ministry said on its website. Azerbaijan said on Sunday that Armenian forces had fired rockets at its second city of Ganja, killing one civilian and wounding four, and threatened to retaliate by destroying military targets inside Armenia.