Oceans away from the sectarian violence in Iraq, the theological differences between Sunni and Shiite Muslims, though muted, exist in the Bay Area.
The centuries-old divide follows no easy pattern.
On the UC Berkeley campus, for years, some Sunni members of the Muslim Students Association refused to participate in prayers if they were led by a Shiite, also known as Shia. The two factions held separate prayers until the 2004-05 school year -- an uncomfortable incongruence in a faith where praying as one is valued.
Yet Sunnis regularly pray at a largely Iranian Shiite mosque in Oakland. And Shiites pray at the Sunni-led Muslim Community Association in Santa Clara, where there are no prohibitions against a Shiite giving the sermon, the khutbah, though leaders concede they can't remember a time a Shiite actually did.
"There is sectarianism within the Muslim community, despite the fact that in terms of theology, we have more in common than differences," said Maha ElGenaidi, president and chief executive of the Islamic Networks Group, a San Jose nonprofit that "strives to inform the American public about misconceptions and the beliefs of Islam."
With Sunni-Shiite relations in global focus because of the violence in Iraq, Shiite-Sunni unity is a popular theme now in the Bay Area. Muslim youth spearheaded a "Muslim Unity Day" event last year at Great America, and the Islamic Society of San Francisco in the Tenderloin hosted a joint prayer with Shiites last year. But tensions are real.