Moscow, Oct 15 : Russian President Vladimir Putin and his Turkish counterpart Recep Tayyip Erdogan have stressed on the importance of observing the ceasefire in the conflict-ridden Nagorno-Karabakh region, the Kremlin said in a statement. During a call on Wednesday, the two leaders addressed the conflict and reaffirmed the importance of observing the humanitarian truce agreed upon during a trilateral meeting between Armenia, Azerbaijan and Russia on October 10 in Moscow, reports Xinhua news agency. They spoke in favour of stepping up the political process, in particular, based on the developments of the Organization for Security and Co-operation in Europe (OSCE) Minsk Group, according to the statement. "The Russian President expressed serious concern over the participation of militants from the Middle East region in the hostilities. "The urgent need for mutual efforts aimed at an immediate cessation of the bloodshed and a transition to a peaceful settlement of the Nagorno-Karabakh problem was stressed," it said. Russia expressed the hope that Turkey would contribute in a constructive manner to the de-escalation of the conflict, considering Ankara's membership in the OSCE. The development comes after Azerbaijan, which is openly backed by Turkey, accused Armenia of violating the ceasefire, just two days after it was imposed, by attacking its second largest city of Ganja and inflicting civilian casualties. However, the Armenian Defence Ministry denied the allegation, saying that it was false information. Renewed clashes between Azerbaijan and Armenia erupted on September 27, with intense battles raging in the Nagorno-Karabakh, a disputed territory which is internationally recognized as part of Azerbaijan but mostly governed by the Republic of Artsakh, a de facto independent state with an Armenian ethnic majority. The area experienced flare-ups of violence in the summer of 2014, April 2016 and this July. Azerbaijan and Armenia have imposed martial law and launched mobilization efforts. In the latest conflict, Nagorno-Karabakh authorities have confirmed that 201 of their personnel and a number of civilians have died. Azerbaijan has said that 22 civilians were killed, but did not provide information about military casualties. Armenia and Azerbaijan went to war over the region in 1988-94, eventually declaring a ceasefire. However, a settlement was never reached. The current fighting is the worst seen since the ceasefire and the two former Soviet republics have been blaming each other. /IANS