Syrian air force jets fired four rockets at an uninhabited section of the border with Lebanon on March 18, according to security sources.
The strike purportedly took place near the Bekaa Valley town of Arsal. No injuries were reported.
The Lebanese border raid and the influx of refugees into neighbouring countries are reminders of the extent to which Syria’s civil war threatens to destabilise the region.
In Jordan’s Zaatari refugee camp hundreds of Syrians demonstrated to mark two years of conflict in their homeland.
One of the activists said: “We are commemorating the start of the revolution, where we went out peacefully and asked for freedom. This led the dictator Bashar al-Assad to respond by killing – killing Syrian people, including children.”
The revolt against Assad’s rule began in March 2011 with peaceful protests in the southern city of Daraa.