BEIRUT- Islamic State fighters seized a Syrian town from Kurdish-led forces north of Raqqa city on Monday, a group monitoring the war reported, two weeks after the jihadist group lost it to the Kurdish fighters backed by US-led air strikes.Rami Abdulrahman, who runs the Syrian Observatory for Human Rights, said Islamic State forces had taken the town of Ain Issa and surrounding areas from the YPG militia. A spokesman for the YPG could not immediately be reached for comment.