A statue of Confederate General Robert E. Lee was defaced at North Carolina's Duke University and there were more arrests on Thursday over the toppling of a similar statue as communities in the U.S. South faced a contentious debate over such divisive monuments.

The discovery came as President Donald Trump stoked the controversy over the statues, echoing white nationalists by decrying the removal of what he said were "beautiful" monuments to the pro-slavery Confederacy.The statue of Lee at the Duke Chapel in Durham, North Carolina, was found early on Thursday with its nose and other facial features chipped off, the university said in a statement. Lee led the Confederate Army during the American Civil War.

The university said that surveillance camera footage was being reviewed for clues as to who was behind the attack on the statue, which stands by the chapel entrance. Security around the site is also being stepped up.

A fresh debate over Confederate symbols has roiled the United States since Saturday's violence during a protest by white supremacists in Charlottesville, Virginia, against the removal of a Lee statue in which one woman died.

Charlottesville Mayor Mike Signer is due to make an announcement on Friday about the statue, public safety at future events, and the legacy of Heather Heyer, the 32-year-old woman who was killed, Signer's office said in a statement.

Also in Durham, four people surrendered on Thursday to face rioting and other charges stemming from the toppling of a statue of a Confederate soldier by protesters there, the Durham County Sheriff's Office said in a statement. That brought the number arrested in connection with Monday's toppling to eight.

More than 100 people meanwhile staged a peaceful demonstration at the local courthouse, the sheriff's office said. Many of them claimed they were involved in Monday's action and demanded to be arrested too, according to local news reports and footage posted on social media.

"Deputies did not arrest rally participants who approached them claiming responsibility for the destruction of a historical statue," the sheriff's office said in its statement.

In Helena, Montana, the city council voted on Wednesday to remove a Confederate fountain from a park. Democratic Governor Steve Bullock said the decision marked the removal of the last monument to the Confederacy in the northwest Rocky Mountains.

San Diego city officials on Wednesday also removed a plaque to Confederate President Jefferson Davis from a downtown plaza, local media said. In Arizona, tar and feathers coated a monument for the Jefferson Davis Memorial Highway, about 40 miles east of Phoenix, local TV news footage showed.