A national Muslim group says it will conduct an investigation into an event at a Philadelphia Islamic center last month during which a group of youngsters sang songs it said were not “properly vetted,” calling that “an unintended mistake and an oversight.”

Youngsters at the Muslim American Society Islamic Center in North Philadelphia are shown in video footage speaking in Arabic during a celebration of “Ummah Day,” said the Middle East Media Research Institute (MEMRI), a Middle East monitoring organization. One girl says "we will chop off their heads” to “liberate the sorrowful and exalted Al-Aqsa Mosque” in Jerusalem, according to the MEMRI.

An English translation of the Arabic is included on the video. The Inquirer has not independently verified the translation.

Ummah is an Arabic word that can mean “community” or “nation.”

“While we celebrate the coming together of different cultures and languages, not all songs were properly vetted,” the Muslim American Society, based in Washington, said in a statement issued Friday. “This was an unintended mistake and an oversight in which the center and the students are remorseful. MAS will conduct an internal investigation to ensure this does not occur again.”

The statement was also posted on the Facebook page of MAS-Philadelphia Center late Friday night.

MAS has more than 50 chapters throughout the United States, according to its website.

“As a faith-based organization dedicated to moving people to strive for God-consciousness and a just and virtuous society, we affirm our long-standing position on our shared values of humanity. We stand resolutely in our condemnation of hate, bigotry, Islamophobia, xenophobia, racism, anti-Semitism and all the illnesses of hate that plague our society,” MAS said in its statement.

In a subsequent statement late Saturday night, MAS said it has been informed that “the person in charge” of the April 17 event has been “dismissed” and that the organization in charge of it “will form a local commission to aid in sensitivity training and proper oversight for future programs.” MAS said it owns the property where the program was held and leases it to the school’s operator.

According to MEMRI, one girl reads: “We will defend the land of divine guidance with our bodies, and we will sacrifice our souls without hesitation. We will lead the army of Allah fulfilling his promise, and we will subject them to eternal torture."

In other videos, students sing songs about the “blood of martyrs” and “Rebels, rebels, rebels.” The videos were posted on the center’s Facebook page, the media monitoring group said, but the videos included in the MEMRI report appear to have been taken down from the center’s page.

The Anti-Defamation League in Philadelphia called the incident “extremely disturbing.”

“Children should not be indoctrinated to hate. These young people should never have been asked to make speeches and dance and lip-sync to songs that glorify violence against Jews and the State of Israel. The conflict between Israelis and Palestinians is deeply complex and painful on all sides, and the only chance for a peaceful future is to teach our children to pursue peace,” the statement read.

The ADL called another report about the event “misleading.” An Arutz Sheva/Israel National News story includes a photo of children in front of what the ADL describes as “a bazooka-wielding extremist,” an image that does not appear to have been taken at the Philadelphia event, the ADL statement read. The article also implies that the event occurred at a Philadelphia school when it occurred at a private religious institution.

Staff writer Patricia Madej contributed to this article.