A wave of car bombs sparked fears of a massive Islamic State uprising as Turkey’s invasion of Kurdish-controlled Syria gathered pace.
One targeted Kurdish fighters at a restaurant in Qamishli, killing one and injuring five people.
It is believed thousands of IS fighters in sleeper cells have been waiting for the Kurds to be diverted so they can rise up and attack.
Meanwhile, the UN said 100,000 refugees had fled the fighting, a figure locals claimed could soon rise to 300,000.
Marvan Qamishlo, of the Kurdish-led Syrian Democratic Forces said: “The whole border is on fire.”