(Reuters) — U.S. lawmakers pounded Facebook on Tuesday, accusing CEO Mark Zuckerberg of pushing for higher profits while being cavalier about user safety, and they demanded regulators investigate whistleblower accusations that the social media company harms children and stokes divisions.

During a Senate Commerce subcommittee hearing, whistleblower Frances Haugen called for transparency about how Facebook entices users to extend their stay on the site, giving them ample opportunity to advertise to them.

“As long as Facebook is operating in the shadows, hiding its research from public scrutiny, it is unaccountable,” said Ms. Haugen, a former employee of the nearly $1 trillion company who turned whistleblower.

“The company’s leadership knows how to make Facebook and Instagram safer, but won’t make the necessary changes because they have put their astronomical profits before people. Congressional action is needed,” Ms. Haugen said.

In an era when bipartisanship is rare in Washington, lawmakers from both parties excoriated the company, illustrating the rising anger in Congress with Facebook amid numerous demands for legislative reforms.

Senator Dan Sullivan, a Republican, said he was concerned about how Facebook and subsidiaries like Instagram affected the mental health of children. “I think we're going to look back 20 years from now and all of us are going to be like ‘what the hell were we thinking?’”

Ms. Haugen revealed she was the one who provided documents used in a Wall Street Journal investigation and a Senate hearing on Instagram's harm to teenage girls. She compared the social media sites to addictive substances like tobacco and opioids.

Panel chair Senator Richard Blumenthal, a Democrat, said Facebook knew that its products were addictive. “Tech now faces that big tobacco jaw-dropping moment of truth,” he said.

He called for Zuckerberg to testify before the committee, and for the Securities and Exchange Commission and Federal Trade Commission to investigate the company.

“Our children are the ones who are victims. Teens today looking in the mirror feel doubt and insecurity. Mark Zuckerberg ought to be looking at himself in the mirror,” Mr. Blumenthal said.

Mr. Blumenthal said after the hearing that he would want to ask Mr. Zuckerberg why he rejected recommendations to make the company's products safer for users.

Despite the criticism, Facebook's share price was up 2.2% at $333.43 in the mid-afternoon on Tuesday.

Coming a day after Facebook suffered an hours-long outage, Haugen pointed to the breakdown in her testimony: "For more than five hours Facebook wasn't used to deepen divides, destabilize democracies and make young girls and women feel bad about their bodies."

As lawmakers criticized Facebook and Mr. Zuckerberg, the company's spokespeople fought back on Twitter, arguing Ms. Haugen did not work directly on some of the issues she was being questioned on.

Ms. Haugen, a former product manager on Facebook's civic misinformation team, left the company with tens of thousands of confidential documents.