Documents purport to show ISIS leader's high school grades

The head of ISIS wasn't the best English student, according to documents posted Wednesday by the German broadcaster ARD. He was better at math and geography.

One of the documents appears to be a high school report card for Abu Bakr al-Baghdadi, who was born Ibrahim Awad Ibrahim. According to the documents, the man who would become the leader of the Islamic State of Iraq and Syria appears to have attended a high school for boys in Samarra, an Iraqi town north of Baghdad, and that he graduated in 1991.

The certificate appears to show that he scored just 57 percent in English language, while scoring 98 percent in mathematics and 90 percent in geography. Overall, he had an 80 average and his behavior was characterized as good.

U.S. intelligence sources reached by CBS News would not comment on the documents.

The Washington Post reports that an official from Samarra's department of education confirmed the certificate was genuine.

If authentic, the documents would be the latest in a string of new information learned about the secretive extremist leader. On Tuesday, CBS News obtained a photo of al-Baghdadi while he served time at Camp Bucca, a U.S. military prison in Iraq in 2004. Documents accompanying the photo show that Baghdadi was employed as a university official at the time of his capture on February 4, 2004. His civilian occupation is listed as secretary.

The reclusive Al-Baghdadi has made only one public appearance since declaring himself caliph, delivering a June sermon at a mosque in Mosul. In November, a purported audio of the ISIS leader emerged, in which he urged his followers to "explode the volcanoes of jihad everywhere."