JERSEY CITY, N.J. (CBSNewYork) — Islamic centers of worship in New Jersey were on alert Wednesday after a mosque in Jersey City received a threatening letter and voice mail.

Inside of the al-Tawheed mosque worshipers were praying for peace. Their Islamic center in Jersey City got a threatening letter referencing Donald Trump, that read in part: “We do not want you here. We do not like you. You are evil.”

“We have a big concern about that. I mean because we never see this kind of letter. This kind of hate,” Islamic Center manager, Kamel Haddouch said.

As CBS2’s Christine Sloan reported, Haddouch opened the type-written letter that came a month after a hateful voicemail.

“And if you guys come over here in mass numbers that you want to do, every American that has the Second Amendment right is going to take their (expletive) gun out and blow you away. I just want you to be prepared for that,” the letter read.

Haddouch has asked worshipers to be careful. The city has also stepped up patrols at all mosques.

“They came into my office as well. We got a lot of calls after Don Trump’s initial statements regarding Jersey City throughout City Hall here,” Mayor Steve Fulop (D) said.

“I have read the terrible things that were in that letter and we are working with local law enforcement and the state police to follow up on that threat,” Chris Rodriguez, Director of the N.J. Office of Homeland Security.

At an interfaith meeting with the state’s Homeland Security Department, Islamic centers across the state were told to be vigilant.

“Call the police. Report what you see, any suspicious activity around mosques,” Ahmed Shadeed, Islamic Center of Jersey City, President said.

“Our message today, no matter if the threat is against a mosque, a synagogue, a temple, we are in this together,” Law Enforcement Chaplain, Rabbi Abe Friedman said.

Muslim leaders at the meeting told all Islamic centers to recheck their voicemails to make sure they did not get any messages of hate.

CBS2 reached out to Donald Trump’s office. No one has responded.

Officials said they have not seen any other threats against Islamic centers in the state.