Sputnik- Russian President Vladimir Putin and his Turkish counterpart Recep Tayyip Erdogan discussed the situation in Syria in a phone convsersation with the participation of Kazakh President Nursultan Nazarbayev, the Kremlin press service said Sunday.

MOSCOW (Sputnik)�� Erdogan has also extended his heartfelt condolences to�Putin over�the crash of�the Russian Defense Ministry's Tu-154 aircraft in�the Black Sea. "A thorough exchange of�opinions on�the situation in�Syria took place [between Putin and Erdogan]. President of�Kazakhstan, Nursultan Nazarbayev, who is on�a working visit to�Russia, took part in�the discussion," the press service said in�a statement.

Tu-154 aircraft with�92 people on�board, including the world-renowned choir of�the country's Armed Forces, the Alexandrov Ensemble, and nine journalists, crashed on�its way to�the Russian airbase in�Syria's Latakia province.

Earlier on�Sunday, Putin and Nazarbayev visited the laboratories of�Biocad, a biotechnology firm in�the Leningrad Region, as�well as�got acquainted with�the production technology and product samples at�the Diakont plant in�St. Petersburg.