JERSEY CITY - Security is being beefed up in Jersey City-area mosques after several of them received threatening letters and voicemails.

Jersey City Mayor Steven Fulop says that the police department will protect the city’s Muslim population in the event of violence. Earlier this week, the Al Tawheed Mosque received voicemails that seemed to suggest gun violence, as well as letter telling Muslims to “go back to the desert.”

Mayor Fulop says that the increase security will be present during certain prayer times, especially on Fridays.

“There’s several large mosques that on the Friday service have 500 people in there,” he says. “Nobody should feel that they’re at risk.”

The imam for the Al Tawheed Islamic Center says those threats have created fear that he is trying to manage among the mosque’s worshippers.

“I said to them many times this week, just to calm down and to feel safe and not to over react,” the imam says.

So far, there have not been any concrete threats or incidents of violence against Jersey City’s Muslim population. Muslim leaders say they've been in touch with the Hudson County prosecutor about the recent threats and have a meeting slated for Thursday.