The plane came in from the southeast late in the afternoon, releasing its weapons in a single pass. Within seconds, scores of finned bomblets struck and exploded on the homes and narrow streets of this small Syrian town.

After the screams and the desperate gathering of the victims, the staff at the local Freedom Hospital counted 4 dead and 23 wounded. All were civilians, doctors and residents said.

Many forms of violence and hardship have befallen Syria’s people as the country’s civil war has escalated this year. But the Syrian government’s attack here on Dec. 12 pointed to one of the war’s irrefutable patterns: the deliberate targeting of civilians by President Bashar al-Assad’s military, in this case with a weapon that is impossible to use precisely.