Injured Syrians have been treated over the border at a hospital in Turkey after an air raid said to have killed 30 people in a rebel-held town.
Doctors said more than a hundred had arrived in Kilis, many in a critical condition.
The strike happened just 20 kilometres away, over the border at Azaz in northern Syria.
It is another sign of how the impact of the Syrian conflict is spreading. Fifty kilometres or so further south from Azaz lies the major urban battleground of Aleppo.
One man said: “War planes, MIG23s or maybe MIG27s shelled our village with bombs weighing at least 900 kilograms and they destroyed the whole area. They did not attack the Free Syria Army but civilians.”
Another man with a blood-stained bandage on his head said: “We were sitting at home and we heard a big explosion, and then we saw smoke rising. Glass and doors shattered everywhere, everything went down on the floor.”
Activists blamed Syrian government forces for the raid in Azaz.
Several houses were reduced to rubble, leaving survivors struggling to treat victims and find others buried in the debris.
There were claims that a government fighter jet bombed the building where a group of Lebanese hostages were being held. Four were reported missing, others injured.
The town is said to be used by rebels to send reinforcements to Aleppo.