Facebook (FB) has revealed additional details about the 32 pages and accounts the social network says were part of a coordinated disinformation campaign.

“We’re still in the very early stages of our investigation, and don’t have all of the facts, including who was behind this,” Facebook COO Sheryl Sandberg told the media on Tuesday, also noting that Facebook couldn’t yet determine the precise goals of these disinformation campaigns.

The effort, which Facebook says has some similarities to Russian’s Internet Research Agency (IRA) that worked to influence the 2016 election, appears to have been meant to foment conflict between right-wing and left-wing social media users who planned to attend competing protests in Washington, D.C. in August.

Facebook chief security officer Alex Stamos said one of the accounts taken down was a co-administrator of an account linked to the Russian Internet Research Agency’s disinformation effort leading up to the 2016 election. The majority of the accounts that were shut down had few if any followers, but around 290,000 accounts followed at least one of the pages.

Growing counter-protesters

The accounts seemed to be interested in building support for a counter-protest to a self-described “white civil rights” rally set to take place in Washington, DC next month. That rally would mark the one-year anniversary of the Unite the Right rally in Charlottesville, Virginia that resulted in riots and the death of one person.

The removed accounts included pages titled Black Elevation, Mindful Being, Aztlan Warriors and Resisters.

Facebook said it briefed law enforcement and lawmakers on the pages and provided evidence to law enforcement personnel.

According to Sandberg, the operators of these pages went to greater lengths to hide their identities than the IRA did in its 2016 election influence campaign. Those tied to the latest disinformation campaign used methods including virtual private networks and internet phone services to mask their locations and paid third parties to run advertisements on their behalf.

In a win for Facebook, if you can call anything related to these campaigns a win, the social network’s new ad monitoring system proved its worth by identifying one of the ads purchased by an entity tied to the disinformation campaign. Once the system recognized the ad was part of a disinformation effort, the suspects didn’t try to run any other ads.

Facebook says the accounts at issue interacted with real accounts interested in the counter-protest event and shared information including transportation and other logistics with users.