MOSCOW (Reuters) - Russian President Vladimir Putin and Armenian Prime Minister Nikol Pashinyan held a third phone call in six days since fighting broke out between Azerbaijan and ethnic Armenians over the territory of Nagorno-Karabakh, the Kremlin said on Friday. Putin and Pashinyan expressed serious concern about the involvement of what the Kremlin termed illegal armed groups from the Middle East in the fighting. Putin reiterated the need for an immediate ceasefire, the Kremlin added.