Violence in Syria has become "ethically unbearable" and the world's governments should immediately end all military interventions there, according to the World Council of Churches (WCC).

In a statement yesterday, WCC general secretary Rev Dr Olav Fykse Tveit said that it was "gravely concerned by the dramatic escalation of the military operations in the conflict in Syria and strictly condemns them".

The WCC warned in September 2013 that "an attack from outside Syria is likely to increase suffering and the risk of more sectarian violence, threatening every community in the nation including Christians". It said then that a non-violent solution to the country's divisions was urgently needed.

Tveit's statement yesterday said: "Sadly, this urgent call remains truer and more needed now than ever. The dramatic daily increase of the number of victims, the haemorrhaging of Syria's population as refugees, and the inability of the international community to find common political solutions have become ethically unbearable. The cycle of extreme violence and its tragic implications on the whole Syrian population have become unacceptable."

He called on governments to support a political peace process, adding: "History has shown tragically and repeatedly that foreign military interventions cannot bring peace and eliminate extremism. On the contrary, they will rather fuel religious tensions and lead to more radicalization."

The civil war between the Assad regime and rebel factions has resulted in at least a quarter of a million deaths and in millions fleeing their homes. Recent support for Assad from Russia in the form of airstrikes and military equipment has turned the conflict into a "proxy war" between Russia and the US, with each country pouring support into its favoured party. While US attempts to train rebels to fight the regime have been an expensive failure, it has just dropped around 50 tons of ammunition and hand grenades to rebel groups in the north of the country.