A number of Syrian opposition groups shunned the peace conference at the Black Sea resort of Sochi claiming that only the Syrian government’s flag was flying at the Russian-hosted event, according to Turkish officials.

Turkey will instead represent the opposition groups at the conference sponsored by Russia, Iran and Turkey, Turkey’s state-run Anadolu news agency reported, citing unnamed sources.

Turkey was also said to be bringing representatives of some Syrian armed groups.

Russia, a key ally of Syrian president Bashar Assad, says it invited 1,600 representatives to the Syrian Congress of National Dialogue but so far only the government and opposition representatives tolerated by it have shown up.

The main Syrian opposition body – the High Negotiation Committee – has boycotted the conference following two days of UN-led peace talks in Vienna last week.

Ankara also blocked the participation of the main Kurdish group, which itself said it would not attend in protest against the unrelenting Turkish offensive launched against the enclave of Afrin in northwest Syria.

Organisers of the Sochi congress intended to bring together Syrians of all stripes to hammer out a new post-war constitution.

More than three dozen other Syrian rebel groups, including influential Islamists, had previously said they would not take part in the Sochi talks.

The UN says over 340,000 people have died and 10 million more have been displaced since the Syrian war began in 2011 as Assad crushed anti-government protests.