A Prophet Muhammad cartoon-drawing contest sponsored by a group of potentially armed bikers got under way Friday outside an Islamic community center in the southwestern U.S. state of Arizona.
Organizers say the rally is in response to to an incident earlier this month in which two gunmen opened fire on a similar contest in Texas where cartoonists were drawing pictures of Islam's Prophet.
Both gunmen were killed following a brief exchange of fire. One police officer was wounded. One of the gunmen frequently worshiped at the north Phoenix mosque were Friday's rally is being held.
"ROUND 2!!!!!!!," declared organizer Jon Ritzheimer on the Friday event's Facebook page. The ex-Marine said the rally will be peaceful, but urged protesters to bring weapons in case of an attack.
"People are also encouraged to utilize there (sic) second amendment right at this event just incase (sic) our first amendment comes under the much anticipated attack," it said.
Ritzheimer has invited thousands of bikers to attend the rally. More than 600 people had RSVP'd on the event's Facebook page by Friday. Local police have promised a heavy presence in case of violence.
The shooting at the Texas cartoon contest was claimed by the Islamic State group that has declared an Islamic caliphate in parts of Iraq and Syria. However, experts have questioned that claim and authorities have found no links between the two gunmen and the extremist organization.
The organizer of the Texas contest where cartoonists were drawing pictures of the Prophet Muhammad was pushing to have the winning entry displayed in Metro stations and on buses around the Washington, D.C., region.
Meanwhile, the board in charge of Washington's subway system has voted to stop showing issue-oriented ads on trains and buses.