The Syrian government and rebels have accused each other of violating a ceasefire in the besieged city of Homs, where the UN is hoping to deliver aid.
Mortar fire was heard early on Saturday, and governor Talal al-Barazi told state media it was caused by "armed terrorist groups".
The anti-government Syrian Observatory for Human Rights blamed President Bashar al-Assad's forces.
Given the violence, it is not clear if the UN aid convoy will enter the city.
Trucks are poised to deliver food, water and medicine to some 3,000 civilians.
http://www.bbc.co.uk/news/world-middle-east-26096116