Air strikes believed to have been carried out by Russian warplanes killed scores of people in the centre of the rebel-held city of Idlib in northwest Syria on Sunday, 20 December. Residents say they distinguish Russian planes that fly at high altitudes in sorties from Syrian helicopters that mainly drop indiscriminate barrel bombs at much lower heights.

"If this is terrorism, that means we are all terrorists, we welcome Islamic terrorism. God is greater than you Bashar. God is greater than the UN. God is greater than the Geneva convention. God is greater than the Riyadh talks. God is greater than all tyrants," yelled one man in the street.

Rescue workers said at least six strikes had hit a busy market place in the heart of the city, several government buildings and residential areas. They said they had confirmed 43 dead but that at least 30 more bodies had been retrieved that had still to be identified.

Russia began a major aerial campaign on 30 September in support of its ally Syrian President Bashar al-Assad. Earlier this year, Assad had suffered a series of setbacks including the loss of Idlib province and areas near the coast which are of crucial strategic importance.

Moscow says its targets Islamic State militants but rebels and residents say they are causing hundreds of civilian casualties through indiscriminate bombing of areas well away from the frontlines.

A coalition of Islamist rebels took Idlib city, the capital of a northwestern province of the same name, earlier this year. It had previously been largely spared by the Russian warplanes.