(CNN) -- A group of atheists has filed a lawsuit to stop the display of the World Trade Center cross at a memorial of the 9/11 terror attacks.

The "government enshrinement of the cross was an impermissible mingling of church and state," the American Atheists say in a press statement.

The group says it filed the lawsuit this week in state court in New York and posted a copy of the lawsuit on its website.

The lawsuit names many defendants, including the state of New Jersey, the city of New York , New York Mayor Michael Bloomberg and New Jersey Governor Chris Christie.

The World Trade Center cross, two intersecting steel beams that held up when the twin towers collapsed on September 11, 2001, is seen as iconic to some.

The cross was moved Saturday from near a church to its new home at the 9/11 Memorial and Museum. There was also ceremonial blessing of the cross in a service led by Father Brian Jordan, a Franciscan monk who ministered to workers clearing the area after the 9/11 attacks.

Joe Daniels, 9/11 Memorial president, said Saturday that the cross is "an important part of our commitment to bring back the authentic physical reminders that tell the history of 9/11 in a way nothing else could.

"Its return is a symbol of the progress on the Memorial & Museum that we feel rather than see, reminding us that commemoration is at the heart of our mission."

But the atheist group says the cross sends a symbol of something different.

"The WTC cross has become a Christian icon," said Dave Silverman, president of the atheist group. "It has been blessed by so-called holy men and presented as a reminder that their god, who couldn't be bothered to stop the Muslim terrorists or prevent 3,000 people from being killed in his name, cared only enough to bestow upon us some rubble that resembles a cross. It's a truly ridiculous assertion."