Demonstrators hold up signs during a news conference Wednesday on the steps of New York’s City Hall. More than 50 leaders of Muslim organizations in New York City are defending plans by developers to build an Islamic community center near ground zero.

New York ? American Muslims are boosting security at mosques, seeking help from leaders of other faiths and airing ads underscoring their loyalty to the United States — all ahead of a 9/11 anniversary they fear could bring more trouble for their communities.

Their goal is not only to protect Muslims, but also to prevent them from retaliating if provoked. One Sept. 11 protest in New York against the proposed mosque near ground zero is expected to feature Geert Wilders, the aggressively anti-Islam Dutch lawmaker. The same day in Gainesville, Fla., the Dove World Outreach Center plans to burn copies of the Quran.

“We can expect crazy people out there will do things, but we don’t want to create a hysteria,” among Muslims, said Victor Begg of the Council of Islamic Organizations of Michigan. “Americans, in general, they support pluralism. It’s just that there’s a lot of misinformation out there that has created confusion.”

On Tuesday, the Islamic Society of North America will hold a summit of Christian, Muslim and Jewish leaders in Washington “to address the growing tide of fear and intolerance” in the furor over the planned New York mosque.

Islamic centers in many cities are intensifying surveillance and keeping closer contact with law enforcement. Adding to Muslim concern is a fluke of the lunar calendar: Eid al-Fitr, a joyous holiday marking the end of Ramadan, will fall around Sept. 11 this year. Muslim leaders fear festivities could be misinterpreted as celebrating the 2001 terror strikes.

“We’re telling everyone to keep their eyes open and report anything suspicious to authorities and call us,” said Ramzy Kilic of the Tampa, Fla., chapter of the Council on American Islamic Relations.

Other efforts around 9/11 aim to fight bigotry. Muslims will clean parks, feed the homeless, and give toys to sick children as part of Muslim Serve, a national campaign to demonstrate Islamic commitment to serving humanity.

Separately, groups are distributing ads to combat persistent suspicions about Islam. One spot, called “My Faith, My Voice,” features American Muslims saying, “I don’t want to take over this country.”

Sept. 11 anniversaries have always been challenging for U.S. Muslims, who have been under scrutiny since the attacks. This year, the commemoration follows a stunning summer in which opposition to a planned Islamic community center near the World Trade Center site escalated into a national uproar over Islam, extremism and religious freedom.

Usama Shami, board chairman for the Islamic Community Center of Phoenix, said a new mosque the congregation has been building for years drew little attention until recently, when some resistance emerged in the neighborhood and from some in city government. Recently, vandals broke into the new building, spilled paint on the floor and broke expensive windows.

Shami believes the ground zero dispute is partly to blame for the trouble, along with passions unleashed by Arizona’s strict new law that would require police to question people about their immigration status if there is reason to suspect they are in the country illegally.

“All of these issues came at the same time,” Shami said. “When things like that happen, I think they bring out the worst in some people.”