Website hosting company Squarespace is removing sites from its platform in the wake of the Charlottesville attack, a company spokeswoman said.

The announcement came as a petition calling for the company to “stop hosting white supremacists” gained traction online.

“In light of recent events, we have made the decision to remove a group of sites from our platform,” Squarespace spokeswoman Lulu Chang wrote in an email. “We have given the site owners 48 hours’ notice. We cannot provide further information at this time.”

The petition, circulated by Joseph Brown, an assistant professor in the political science department of the University of Massachusetts Boston, criticized Squarespace for continuing to host the websites of Richard Spencer’s National Policy Institute and Identity Europa, a white supremacist group, despite repeated complaints.

“Squarespace’s continued hosting of these sites constitutes an in-kind contribution to neo-nazis, white supremacists, and the violence they promote — in Charlottesville and elsewhere,” the petition said. “WE MUST NOT STAND FOR THIS.”

Spencer and Nathan Damigo, the founder of Identity Europa, were not immediately available for comment.

Brown said he posted the petition in March after a white nationalist group left racist recruitment fliers at his school, an institution where the majority of students are minorities. The petition had about 60,000 signatures as of Thursday morning.

“We serve people targeted by these racist organizations,” he said in a telephone interview. “And so when they visited our campus it was really an attack on our students — an attack on what UMass Boston stands for.”

Though Brown alerted Squarespace to the problem, the company initially told him it would not take any action.

“With so many diverse viewpoints expressed on Squarespace, there are sometimes sites containing content that others find offensive,” a company representative wrote in an email to Brown in March. “However, Squarespace strongly supports the principles of freedom of speech, the marketplace of ideas, and empowering our users to share their opinions, even if those opinions are controversial or unpopular.”

After the Charlottesville violence, other companies have removed racist websites. GoDaddy delisted the Daily Stormer, a prominent neo-Nazi website; the website of Vanguard America, the group that driver accused of the Charlottesville killing was photographed with, was removed by WordPress as well.

Brown said he welcomes the change, but wishes Squarespace would have acted sooner.

“Although Squarespace said it’s doing the right thing, it took so many weeks and other companies doing the right thing to make Squarespace take action,” he said.