Updated at 7 p.m. to note that a woman was standing guard over the statue.

Someone vandalized the statue of Confederate Gen. Robert E. Lee in an Oak Lawn park overnight.

A city crew was called to Lee Park on Turtle Creek Boulevard about 8 a.m. Saturday to power-wash the graffiti from the statue.

When crew members arrived, they said they found the word "Nazis" scrawled on the statue in spray paint.

While the parks crew was cleaning the statue, one crew member said, a vandal walked up, urinated on the statue and ran away. A city representative and the cleanup crew's manager, however, denied that account, and police could not confirm it.

Authorities will post extra police patrols at the park to prevent any further vandalism, Dallas police spokeswoman Debra Webb said.

Lee Park ranger circling Robert E. Lee statue, says he's on guard in case someone tries to vandalize it. pic.twitter.com/mT5QEVTd5y — Allison Harris (@AllisonFox4News) August 19, 2017

Such vandalism is unacceptable to Mayor Mike Rawlings, who has called the city's Confederate monuments a "symbol of injustice" and set up a task force to decide how to handle them.

"We will not tolerate unlawful behavior, including acts of vandalism or violence, regardless of one's beliefs," the mayor said in a written statement Saturday. "I call on all citizens who plan to exercise their First Amendment right to do so in a civil and peaceful manner."

Paul and Lynette Garrett, a retired black couple, took photos of the statue Saturday morning that they plan to post online before attending a rally against white supremacy outside Dallas City Hall this evening.

The Garretts, who now live in Farmers Branch, used to live near the park in the 1980s and would picnic there. They didn't associate it with the Confederate general at the time but believe the statue should be placed elsewhere, like a museum.

"I think that if they do decide to bring them down they should go somewhere because it is a part of our history," Paul Garrett said.

Lynette Garrett thought about what she'd tell her grandmother, who was a slave.

"She would think that this is 2017: This should all be behind us," she said. "We're here because it shouldn't be this way."

1 / 5A city parks crew packed up power-washing equipment after cleaning the statue of Robert E. Lee at the Oak Lawn park named in tribute to the Confederate general.(Michael Hamtil / Staff Photographer) 2 / 5The statue of Confederate Gen. Robert E. Lee at Lee Park in the Oak Lawn neighborhood.(Andy Jacobsohn / Staff Photographer) 3 / 5A detail of the plaque on the statue of Robert E. Lee in Oak Lawn.(Andy Jacobsohn / Staff Photographer) 4 / 5Robert E. Lee is frozen in motion as if he and his horse, Traveller, are about to step into Turtle Creek Boulevard. (Andy Jacobsohn / Staff Photographer) 5 / 5Fawaz Anwar of Carrollton looks up at a statue of Confederate Gen. Robert E. Lee at Lee Park in the Oak Lawn neighborhood.(Andy Jacobsohn / Staff Photographer)

Saturday afternoon, a woman from Mississippi stood watch over the statue, KXAS-TV (NBC5) reported.

Carol Mize from Biloxi, MS stands watch at the Statue of Robert E.Lee. Vandals painted part of the display last night. @NBCDFW #NBCDFWNow pic.twitter.com/SBC9XwoKYs — Ken Kalthoff (@KenKalthoffNBC5) August 19, 2017

It's not the first time the Lee statue in Oak Lawn has been defiled. In July 2015, someone spray-painted "SHAME" on its base, just two weeks after a group of protesters held an "undedication" ceremony at the park.

The statue and other monuments across the country have become flash points in the debate over whether such tributes to the Confederacy belong in public places.

On Friday, four black members of the City Council called for Dallas to remove its Confederate monuments — but only after citywide discussions can take place.

"Taxpayer dollars should not support vestiges of racism and white supremacy," said council member Kevin Felder, who represents South Dallas and Fair Park.

Rawlings said he wants the council to take action on the fate of the Lee statue and other such monuments by no later than Nov. 8.

"But it is critical that we go about this process in a way that makes our city more united," the mayor wrote. "Let's use this opportunity to listen to one another, to learn from one another and to make our city stronger."

The nationwide controversy boiled over last week in Charlottesville, Va., where a white supremacist rally ended when a demonstrator drove into a crowd, killing a counterprotester.

In response, a rally against white supremacy is planned outside Dallas City Hall from 7:30 to 9:30 tonight.

Dallas police say they will be patrolling the rally in force.

The rally was news to Michael Yawitz, who lives near Lee Park and dropped by after the cleanup crew sprayed off the statue. He passes the statue of Lee and a nameless Confederate soldier every day and says he doesn't think twice about it.

"Most Americans see two men on horseback, and they don't know when the Civil War was fought," the 56-year-old avionics technician said. "If we don't remember our history we're due to repeat it. I don't look at it as racism."

Staff photographer Michael Hamtil contributed to this report.