Mark Zuckerberg announced Thursday Facebook will turn over the contents of 3,000 ads purchased by a Russian agency to Congress.

The ads are being investigated as part of the probe into Russian meddling into the U.S. election.

Facebook has briefed members of Congress and also provided the ads and other information to Robert Mueller, the special counsel in charge of the Russia investigation, the company said.

In all, the accounts purchased some 3,000 ads between June 2015 and May 2017. While the ads didn't specifically reference the election, a candidate or voting, they nevertheless allowed "divisive messages" to be amplified via the social media platform, the company's chief security officer, Alex Stamos, said in a statement Sept. 7.

In addition to the 470 accounts that appeared to be run from Russia, Stamos said its investigators also discovered an additional $50,000 in spending via 2,200 ads that "might have originated in Russia," even including ads purchased by accounts with IP addresses in the U.S. but set to Russian in the language settings.

Lawmakers have said they want to know more about the content of the ads pushed out by the Russian-based Internet Research Agency and whether they targeted specific voters or locations in the United States.

Facebook has come under intense pressure since the election to curb the flow of false information. After the election, it updated its advertising policy to say it wouldn't run spots that are "illegal, misleading or deceptive, which includes fake news."