A suicide bombing has hit a U.S.-Kurdish convoy in northern Syria, making it the second suicide attack to target American troops in five days. On Thursday, two U.S. soldiers and two other Americans working for the coalition in Syria were killed in a suicide bombing in Manbij in an attack later claimed by ISIS. The Syrian Observatory for Human Rights says two U.S. soldiers were injured in Monday's attack and five of their Syria Democratic Forces escorts were killed. The war monitor reported: “The bombing was caused by a suicide bomber who detonated himself in a booby-trapped vehicle he was driving, he targeted a column of the U.S. Forces accompanied by members of the Syria Democratic Forces to protect them during their roam in the area.” Monday's attack happened in the north-eastern Al-Hasakah province. The coalition said: “We can confirm a combined U.S. and Syrian partner force convoy was involved in an apparent VBIED attack today in Syria. There were no U.S. casualties. We will continue to review the situation and provide updates as appropriate.”