Russian warships in the Mediterranean Sea fire cruise missiles at targets near Aleppo on Friday, a further sign of Moscow's broadening military effort in Syria days after it began to fly bombing missions from an airbase in Iran.

Islamic State fighters capture territory from Syrian rebels near the Turkish border and inch closer to a town on a supply route for foreign-backed insurgents fighting the jihadists, a monitoring group said.

US Secretary of State John Kerry is in Geneva in an attempt to bolster a fragile, partial ceasefire in Syria.

At least 11 civilians were killed in Syria's second city Aleppo in one of the highest single tolls since a fragile truce came into force, a monitor says.