Democratic Majority for Israel CEO and President Mark Mellman issued a statement on Oct. 16 expressing concern that Sen. Bernie Sanders (I-Vt.) has accepted recent endorsements for his presidential campaign from supporters of the boycott, divestment and sanctions (BDS) movement. He also said they “have repeatedly made anti-Semitic statements.”

Mellman said, “It’s deeply disturbing to find a candidate who claims to be ‘100% pro-Israel,’ opposed to BDS and a fighter against anti-Semitism surrounding himself with a number of surrogates and endorsers who hate Israel, support BDS and have repeatedly made anti-Semitic statements.”

He added that the pro-Israel group told Sanders about their concerns, “beginning with his naming of noted anti-Semite Linda Sarsour as an official surrogate. Unfortunately, the only responses we have received from the Senator are more hostile choices on his part.”

Mellman’s statement comes after it was reported on Oct. 15 that Reps. Alexandria Ocasio-Cortez (D-N.Y.), Ilhan Omar (D-Minn.) and Rashida Tlaib (D-Mich.) will be endorsing Sanders’ presidential candidacy. Omar said in a statement that she is endorsing Sanders because he “is leading a working-class movement” and “is fighting to end our forever wars and truly prioritize human rights in our foreign policy—no matter who violates them.” Both Omar and Tlaib are avowed BDS supporters.

On Oct. 9, Palestinian-American comedian Amer Zahr announced on Twitter that he was named as a surrogate for Sanders. Zahr, who is also a BDS supporter, tweeted that “American Jews are starting to realize that Israel is their ISIS” and that calling Israel supporters “’scumbags,’ ‘pigs,’ and ‘bastards’ is not necessary. ‘Zionist’ is sufficiently insulting,” according to the Jerusalem Post.

The Sanders campaign did not respond to the Journal’s request for comment.

UPDATE: Tlaib has denied that she is endorsing Sanders, telling the Detroit Free Press on Oct. 16, “I have not made any endorsement at this time.”