A major explosion shook the Al Ittihad University in the city of Raqqa which is transformed to headquarter of the American occupied forces. The huge explosion took place in the outskirts of the University of the occupied town. 55 members of the so called SDF (forces who collaborate with USA were killed, additionally to the death of 14 American militars . At about 100 are estimated the injured as several ambulances run to evacuate them. Another source indicates that a bomb explosion took place inside a military vehicle of the International Alliance. The same source added that the US forces were obliged to return to their administration base. All reports confirm that several Americans have been killed.