Clashes between Russia-backed Syrian regime forces and the Islamic State group have killed more than 50 fighters on both sides in two days, a Britain-based war monitor said on Saturday. Fighting and Russian air strikes in the central desert province of Homs since late Thursday have claimed the lives of 20 pro-government fighters and 31 militants, the Syrian Observatory for Human Rights said. "The fighting started in the night of Thursday to Friday with a jihadist assault on regime positions" near the town of Al-Sukhna, Observatory head Rami Abdel Rahman said. ISIS militants have retained a roving presence in Syria's vast Badia desert, despite losing their last shred of territory last year. They regularly carry out attacks there. ISIS declared a cross-border "caliphate" in large parts of Syria and neighbouring Iraq in 2014, but several military campaigns against it chipped away at that proto-state and eventually led to its territorial demise. Syria's war has killed more than 380,000 people since it started in 2011 with the repression of anti-government protests, before evolving into a complex conflict involving world powers and militants. Diplomatically, Iran, Russia and Turkey, which support opposing sides in Syria's war, held talks on Wednesday to harmonise efforts to bring peace to the country, whose conflict has entered its 10th year. Iranian President Hassan Rouhani said there was "no military solution" for Syria, during the video conference with his Russian and Turkish counterparts. Russian President Vladimir Putin denounced newly imposed US sanctions that he said were aimed at "suffocating" Syria, while Turkey's Recep Tayyip Erdogan called for peace and security to be restored in his country's southern neighbour. The talks were the first since September in the so-called Astana format, three-way talks between the key foreign powers in the Syrian conflict. Iran and Russia have been staunch supporters of President Bashar Al Assad, while Turkey has called for the ouster of his regime and backed opposition fighters. Mr Rouhani told the conference that "the Islamic republic believes the only solution to the Syrian crisis is political and not a military solution." "We continue to support the inter-Syrian dialogue and underline our determination to fight the terrorism of Daesh (the Arabic acronym for ISIS), Al Qaeda and other related groups," he said.