Pictures have emerged of what Syria says is the site of a deadly strike by US helicopters on its territory.
Syria says eight people, four of them children, were killed when four US aircraft travelled eight miles inside Syrian airspace from Iraq.
Damascus said the dead were unarmed civilians on a farm, saying the strike hit a building under construction just outside Sukkariyeh, near the border with Iraq.
As they buried loved ones, angry villagers carried Arabic signs reading, "We will not bow to America. No, No, No to America."
Speaking in London, Syria's Foreign Minister Walid Muallem accused the US of an act of "criminal and terrorist aggression."
The US refused to confirm or deny the raid, although an unnamed official did say that its forces had mounted a "successful" raid against "foreign fighters" threatening US forces in Iraq.