Twitter (NYSE:TWTR) has announced it is changing its advertising policies to provide more information about the ads running on its site. An advertising transparency center created by the company will reveal details about all ads running on the platform. Twitter said it would disclose who had paid for the advertisement and allow users to find information about the buyer, including ad spending history and ad targeting practices.

Election and issues-based ads would be subject to more disclosure rules than non-election ads. Twitter also said it would also create stricter requirements for who could purchase political ads. Advertisers will no longer be able to create ads that are only visible to their targeted recipients. The company said it would also limit targeting options and create stronger penalties for violators.

Political ads for a candidate or party would carry a special label to make them stand out. In a blog post, Twitter said, β€œTo make it clear when you are seeing or engaging with an electioneering ad, we will now require that electioneering advertisers identify their campaigns as such and we will also change the look and feel of these ads and include a visual political ad indicator on each.”

The moves are part of a new transparency push in the wake of the 2016 election. Twitter said it would put some of these changes in place in the coming weeks. The changes will start in the United States and then expand globally.

Congress is investigating the fraudulent activity rampant on social media during the last presidential election. Fake accounts linked to Russia are said to have easily bought thousands of ads promoting hot-button issues to sow chaos before the election. Twitter discovered about 200 accounts linked to Russian efforts to influence the election, but researchers have said that there may be as many as 600 such accounts on the site.

The leaders of Twitter, Facebook and Google are scheduled to appear for hearings before the Senate and House Intelligence Committees on Nov. 1 regarding the matter. Facebook uncovered thousands of dollars of spending on ads by Russian troll farms pretending to be American-based advocacy groups during the presidential race. Facebook has also said it would establish a system to begin revealing what ads are running and what entities are behind them.

Three Senators have already introduced a bill to require more disclosure from digital political ads. Senator Mark Warner of Virginia, the leading Democrat on the Senate Intelligence Committee, Senator Amy Klobuchar, a Democrat from Minnesota, and Senator John McCain, a Republican from Arizona, produced a bill that would require digital platforms to report who bought political ads on their sites. Ms. Klobuchar said the companies should not be left to police themselves.