GARLAND, Texas – Police are braced for hundreds of protesters Saturday at an Islamic fundraiser. Menacing social media posts have organizers worried about violence.

About a dozen protesters provided a preview Friday night in Richardson, as Muslims came for prayers at the Islamic Association of North Texas. About 10 protesters carried signs quoting Christian scripture.

Police made space for them on the sidewalk, where they screamed through a bullhorn as worshipers entered the mosque.

"Time to repent," yelled Ruben Israel. "Islam is filled with murder! This is your wake up call."

Israel is a Los Angeles street preacher. He shouted through the loud speaker, "How many of you Muslims are terrorists?"

We asked if he saw a distinction between families going in, and terrorists who committed the murderous attacks in Paris.

"I see common ground," he replied.

Israel came to protest an event called Stand with the Prophet Against Terror and Hate. It's a fundraiser by the Chicago-based Islamic multimedia foundation Sound Vision.

About 500 people have paid to hear a number of Islamic speakers, "To raise money for their program to educate others about Islam and Muslims for the purposes of combating Islamaphobia, terrorism and hate," explained Alia Salem with the North Texas chapter of the Council on American Islamic Relations, or CAIR.

Because the Islamic group rented Garland ISD's Culwell Center for the event, opponents blasted school board members this week.

"I certainly don't think you need people there who want to destroy this country," one man complained.

A district spokesman said Garland ISD does not discriminate against facility renters based on religion.

Social media posts went much further than mere complaints. There was talk of bullets and dynamite.

"They have been turned over to law enforcement and the FBI," Salem said.

Ruben Israel says his group, Bible Believers, is loud, but non-violent. When prayers began inside the mosque, they turned off the bullhorn.

Outside the Cullwell Center in Garland Friday, police raised two watch towers and posted a squad car for security.