There remains no word on casualties after a Syrian warplane bombed the rebel-held town of Ras al-Ain, barely metres from the Turkish border.
The attack sent scores of Syrian civilians rushing for safety in the neighbouring country.
Helicopters also strafed targets near the town, which fell to rebels on Thursday.
A Reuters reporter in Ceylanpinar - the Turkish settlement that borders Ras al-Ain - said the warplane flew right along the border and appeared at one point to have entered Turkish airspace.
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.