A New Jersey mosque has been receiving hate messages in the mail and on the phone, leaving worshipers worried for their safety.

In a recent letter sent to the Al Tawheed mosque in Jersey City, the author wrote, in part: "We do not want you here. We do not like you. You are evil."

The rest of the typewritten note is offensive and unsuitable for publication.

Kamel Haddouche opened the letter Monday and has since turned it over to Jersey City police.

"It's really a big concern for us now," he said.

The letter comes a month after a threatening voicemail was left for members of the mosque.

"Every American that has a Second Amendment right is going to take their (expletive) gun out and blow you away," a woman said in the phone message. "I just want you to be prepared for that."

Muslim leaders at the mosque urged their followers to travel in groups and not respond to threats or rude comments. Jersey City has also promised a stronger police presence outside city mosques.

"They are an important part of our community and we want to make them feel safe, and we don't condone this rhetoric in any way," said Mayor Steve Fulop, a Democrat.

Muslim Americans say tension has been rising since the terrorist attacks in Paris and San Bernardino. But it was Donald Trump's proposal Monday to ban all Muslims from entering the U.S. that has the Jersey City community truly worried.

"I'm afraid someone will get hurt," said Ahmed Shedeed. "This is not the America that we know and love, where we live in peace."

Jersey City has the second-largest Muslim population in New Jersey, after Paterson. The city has been dragged into some of the anti-Muslim rhetoric swirling around Trump's campaign, like when he claimed last month that he saw "thousands of people" there "cheering" as the twin towers came down on 9/11.

Elected officials, law enforcement officials, community leaders and media reports have disputed that account, saying there was no proof that happened.

A spokesman for the Council of American-Islamic Relations called Trump's comments Monday "reprehensible," and he added that peace-loving Muslims have the most to lose from ISIS.

"ISIS are damning my religion, my faith that I love," said Abdul Mubarak-Rowe, of CAIR. "They are an enemy to everybody."

Gov. Chris Christie also blasted Trump's proposal Monday, saying on a radio show, "This is the kind of thing that people say when they have no experience and don't know what they're talking about."

He added that the government needs to be taking the opposite approach and embracing and cooperating with "peaceful Muslim Americans who want to give us intelligence against those who are radicalized."

At the Alghazaly School in Jersey City, second-grade teacher Aayah Elhosary said Tuesday she is proud to wear the hijab, or head scarf, just like she's proud to be American. She said she urges her students to act and speak with compassion, and even tells them to wish their neighbors a merry Christmas.

"How they act has an impact on how people see them, so I tell them to be kind to everyone, and to all people, not just Muslims," she said.