Ilhan Omar, the Democratic congresswoman from Minnesota, apologized Monday afternoon after receiving backlash for controversial tweets she had made about the Israel lobby in the United States.

Republicans and Democrats criticized Omar after she tweeted that Republican support for Israel is linked to money from lobbyists, particularly from the powerful pro-Israel group American Israel Public Affairs Committee (AIPAC). Her comments were denounced by House Democratic leaders as “anti-Semitic tropes.”

“Anti-Semitism is real and I am grateful for Jewish allies and colleagues who are educating me on the painful history of anti-Semitic tropes,” Omar tweeted Monday afternoon. “We have to always be willing to step back and think through criticism, just as I expect people to hear me when others attack me for my identity. This is why I unequivocally apologize.”

Omar, along with fellow freshman Rep. Rashida Tlaib, D-Mich., are the two first Muslim women to serve in Congress.