Turkish police fired tear gas and water cannon to keep people on the Turkish side away from the border fence while a Syrian warplane - supported by helicopters - attacked just over the border.
In neighbouring Ceylanpinar, anxious residents crowded outside a teahouse to watch the bombing.
One unnamed Turk said:
I thought the Turkish government said it wouldn't allow these helicopters to come so close to the border. Look, they're coming inside our border.
Thousands more refugees pour across the border to escape the war in Syria, whilst Turkey says the conflict is threatening their security.
A suggestion that David Cameron has gone "out on a limb" over Syria has been rejected by his official spokesman.