Ben Carson sparked outrage from his fellow Republican presidential candidates and members of the Muslim community after stating on Sunday that a Muslim man or woman should not be elected president of the United States.

“I would not advocate that we put a Muslim in charge of this nation. I absolutely would not agree with that,” the retired neurosurgeon told NBC’s “Meet the Press.”

The Republican candidate pointed as a warning to the Boston Marathon bombers, Tamerlan and Dzhokhar Tsarnaev, who immigrated to the United States as refugees from Kyrgyzstan, before carrying out the 2013 bombing that killed six people and injured 280.

Carson further argued that Islam as a religion is incompatible with the American Constitution, and a presidential candidate’s faith should be considered during the election.

“If it’s inconsistent with the values and principles of America, then of course it should matter,” he added.

Presidential candidate Sen. Ted Cruz reacted by reminding that the U.S. Constitution says there is no religious test for public office.

“You know, the Constitution specifies there shall be no religious test for public office and I am a constitutionalist,” he said.

In a Fox News interview, presidential candidate Sen. Lindsay Graham called on Carson to apologize to all Muslim Americans for the remark.

Democratic Congressman Keith Ellison of Minnesota, the first Muslim to be elected to Congress, described Carson’s comments as “fear mongering.”

“The freedom of religion is a founding principle of our nation,” Ellison said, according to TIME Magazine. “Every American should be disturbed that these national figures are engaging in and tolerating blatant acts of religious bigotry.”

The Council on American-Islamic Relations further called on Carson to drop out of the presidential race.

“Mr. Carson clearly does not understand or care about the Constitution, which states that ‘no religious test shall ever be required as a qualification to any office,'” said the group’s national executive director, Nihad Awad.

Carson campaign spokesman Doug Watts responded to the outrage and clarified that Carson did not suggest that a Muslim should be prevented from running for office.

“He [Carson] just doesn’t believe the American people are ready for that,” Watts said.

“Dr. Carson is a strict adherent to the First Amendment — freedom of religion. That includes people of all faith,” the spokesman continued.

“He has great respect for the Muslim community, but there is a huge gulf between the faith and practice of the Muslim faith, and our Constitution and American values.”

Carson, who is a Christian, has been gaining strong support from Evangelical churchgoers and especially those who describe themselves as “highly religious” in the polls, going up against the current frontrunner Donald Trump.

The retired neurosurgeon has also spoken out on the growing crisis of Syrian refugees seeking asylum in Western states, and said that the U.S. should not allow any such refugees until a stricter screening process is implemented.

“I would recognize that bringing in people from the Middle East right now carries extra danger and we have to be extra cautious,” Carson said.

“You know, the typical mechanisms that we use for screening people, perhaps, have to be enhanced.”