Syria convoy attack: Russia drone footage shows 'militant mortar'

The US has said it holds Russia responsible for a deadly attack on an aid convoy near the Syrian city of Aleppo on Monday.

Russia strongly denies involvement of its own or Syrian planes, and says the incident was caused by fire on the ground and not by an air strike.

The Russian defence ministry has released drone footage purportedly showing a pick-up truck towing a large-calibre mortar belonging to militants accompanying the convoy.