Palestinian stabs rabbi in Arab East Jerusalem
The incident happened in the Old City of Jerusalem, which from roughly 1870-1948 had a majority Jewish population. The Muslim Quarter, where this incident occurred, used to be called the "Mixed Quarter" because Jews, Muslims and Christians all lived there, until the 1929 pogroms against the Jews.
While there are parts of East Jerusalem that are predominantly Arab, to categorize all of East Jerusalem as "Arab" is an editorial comment, not a statement of fact. To say that the Old City is "Arab East Jerusalem" is pretty dishonest, even if there are more Arabs living there now than others. It is effectively enshrining Jordan's illegal annexation and ethnic cleansing of East Jerusalem for 19 years as being legitimate, and the existence of Jewish-owned lands in East Jerusalem as illusory. It is also meant to make the existence of a yeshiva in the Old City's "Muslim" quarter look as if it is a recent "settlement," when in fact the yeshiva is occupying the building of the only Jewish school or synagogue that was not destroyed by Jordan in 1948 (Torat Chaim, est. 1886.) All additional buildings that Ateret Cohanim own were purchased legally.
East Jerusalem is much larger than the Old City, of course, and using the term "Arab East Jerusalem" to describe something that happened in the Old City would be like saying that the Upper East Side crane accident over the weekend occurred in "New York State." It appears that Reuters is specifically choosing this terminology in order to render Israeli building in other parts of East Jerusalem, such as in Har Homa, as being illegitimate, since Reuters considers it "Arab" land - notwithstanding that most of Har Homa was also owned by Jews in 1948.