Protesters in California demand end to U.S. aid to Egypt following the massacre outside a Coptic church in Alexandria, where a bomb blast killed 21 people and wounded more than 100 others during New Year’s prayers. 

Click here for video of prayers and bomb blast. 

U.S. President Barack Obama called the attack “barbaric and heinous.”  

Last year, Muslim terrorists gunned down nine Copts outside a church on the eve of the Coptic Christmas.  The Egyptian government called the slaughter an “isolated incident.” 

California Copts demonstrated in the rain in Los Angeles on Sunday to "show America what's happening in Egypt,” 60-year-old Adib Ghobrani told the Beverly Hills Courier. International Christian Concern official Aiden Clay called on Americans to complain to Washington, which provides Cairo with more than $1 billion aid annually.

Egypt is the largest recipient of foreign aid after Israel, and has received more than $36 billion from the U.S. since it signed a peace treaty with Israel in 1979.

Protests following the attack were also held in Alexandria and Cairo, where Egyptian riot police faced off against protesters. Government spokesmen issued a call for national unity, but human rights leaders have charged Cairo with denying the extent of the 40-year tensions between Coptics and Muslims.

The suicide bombing represented a drastic escalation in Muslim violence against the Coptic minority, which comprises approximately 10 percent of Egypt’s population. Egypt blamed “foreign fingers,” possible Al-Qaeda, for the terrorist attack, Egypt's worst in recent memory, but The New York Times reported that Egyptian authorities said local citizens apparently were behind the bombing.

An international Christian organization charged two weeks ago that Egyptian police opened fire and shot live ammunition at unarmed Copts at a rally, where two people were killed.