The group is the Muslim American Society (MAS), and apparently they were so proud of the singing video, they posted it on Facebook. When called out, MAS apologized for it being posted to Facebook without vetting, but not for the song being taught to children.
MEMRI [the Middle East Media Research Institute] posted portions of the video footage along with English subtitles. Kids dressed in Islamic attire are singing: ‘We will chop off their heads, and we will liberate the sorrowful and exalted Al-Aqsa Mosque. We will lead the army of Allah fulfilling His promise, and we will subject them (the Jews) to eternal torture.'”
One commenter noted: “Only a Democrat believes we need more of this culture here.”