Muslim Americans responded with a mix of frustration, exasperation and anger to what many see as a growing wave of Islamophobia fueled by two of the Republican Party's most popular presidential candidates, Donald Trump and Ben Carson.

At the Islamic Institute of Orange County, which houses a mosque and a school in Anaheim, in southern California, tensions were already mounting since a group of white men screamed at mothers and children arriving at the center on this year's anniversary of the Sept. 11, 2001 attacks, calling them cowards who did not belong in America.

Many of the country's 2.8 million Muslims say such tensions could become uglier during a presidential race that they fear is already tapping a vein of anger and bigotry.