More than 200 protesters, some armed, berated Islam and its Prophet Muhammad outside an Arizona mosque Friday in a provocative protest that was denounced by counterprotesters shouting "Go home, Nazis," weeks after an anti-Muslim event in Texas came under attack by two gunmen.

The anti-Muslim event outside the Islamic Community Center of Phoenix was organized by an Iraq War veteran who posted photos of himself online wearing a T-shirt with a crude slogan denigrating Islam and waving the U.S. flag.

As the event got underway, demonstrators on both sides screamed obscenities at each other as police in riot gear swiftly separated the two groups, each with about 250 people, using police tape and barricades.