Muslim organizations in the United States have extended condolences to the families of those killed in Thursday's deadly bombings in London. Muslims in California have joined other religious leaders in condemning the attacks.

Friday, Christian, Jewish, and Muslim leaders joined law enforcement officials at the Islamic Society of Orange County, one of California's largest mosques. Edina Lekovic, a spokeswoman for the Muslim Public Affairs Council, says the London bombings violate all the principles of her faith.

"The Muslim Public Affairs Council, as well as the Council on American Islamic Relations, stand in solidarity with Muslims across the United States, as well as Muslims around the world, in condemning terrorism," he said "This is not the first the first time we have done it, and it's not the last time that we will do it."

The spokeswoman says 600,000 Muslims live in southern California, making the region one of the largest Muslim centers in the United States. Muslims are also concentrated in New York, Detroit and Chicago. Estimates of the size of the U.S. Muslim population are uncertain, but range from five to seven million.

The Council on American Islamic Relations issued a statement Thursday condemning what it called the "barbaric attacks" in London. The California-based charity Islamic Relief called the bombings "a crime against all of humanity."

The Muslim Council of Britain and other British Islamic groups have issued similar condemnations, and urged Muslims to help in the recovery effort.