The Freedom From Religion Foundation, a national atheist organization, recently got word that a Las Vegas church building had some crosses on its walls — and the group wasn't too happy about that.

But this isn't just any church building. The sticking point is that a public school is leasing it — and therefore the FFRF said the crosses on the walls aren't constitutional.

So the Wisconsin-based activist group sent a letter to officials with Discovery Charter School this month, telling them to remove religious symbols in the building it's leasing from Mount Olive Lutheran Church, the Las Vegas Review-Journal reported.

“The appearance that the school endorses Christianity is overwhelming and undeniable,” FFRF legal fellow Christopher Line wrote, the paper said. “If [Discovery] wishes to continue leasing from a religious organization, it must ensure that the school environment is constitutionally compliant.”

What did the school say?

John Haynal — appointed to turn around struggling Discovery Charter — confirmed that two crosses inside the building it's leasing from the church were removed when the school moved to the property in July, the Review-Journal said. The new Sandhill campus is for students in kindergarten through fourth grade.

He also told the paper that a banner with cross symbol welcoming visitors to Mount Olive will be moved away from the school entrance and to the front of the church by Oct. 1, and that Discovery’s blue banner will replace the church banner.

Discovery Charter also shares space in the church’s fellowship hall, which the school uses as a cafeteria and for art for its kindergarten, Haynal told the Review-Journal.

Who complained?

Haynal told the paper he attributes the complaint about the crosses to an individual unhappy with changes that came after he was appointed last year by state charter school officials to run Discovery, which was weathering struggling elementary grades.

The Freedom From Religion Foundation didn't name the complainant, the Review-Journal said, but Line said it came from a local resident concerned about the school moving into a church.

Haynal added to the paper that Discovery got a similar complaint from Americans United for Separation of Church and State, urging the school to relocate to a space without religious connections.

But what about the cross in front of the church sanctuary?

While Line said he's pleased the two crosses in the leased church building were taken down, the Review-Journal said a cross at the front of the church sanctuary could cause legal issues.

Line told the paper that if students aren't entering near the cross and don't see it every day, that might pass muster.

“It really is just about taking steps to make sure that it’s very clear that the public school is not affiliated with the church’s teaching,” Line added to the Review-Journal.

But Haynal argued to the paper that he has no say over religious symbols on church property the school isn't leasing.

“I give my word to my public, to my parents, and to my students that this will be a public school environment second to none,” he added to the Review-Journal. “And only that.”