Protesters shouting about "Sodom and Gomorrah" interrupted South Bend, Indiana, Mayor Pete Buttigieg on Tuesday at an Iowa campaign rally.

Buttigieg hopes to become the first openly gay president in American history.

One of the men who shouted about the biblical cities destroyed by God's wrath for their sinful ways was Randall Terry, a Christian activist who founded the anti-abortion rights group Operation Rescue. The organization says it split with him 18 years ago and now considers him too radical.

The crowd at the Des Moines rally drowned out Terry's shouts by cheering Buttigieg’s name.

"The good news is, the condition of my soul is in the hands of God, but the Iowa caucuses are up to you," an unshaken Buttigieg responded, pointing at the crowd.

CNN's Jeff Zeleny reported that Buttigieg was interrupted three times by protesters affiliated with Terry.

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Another video from the rally showed one of the other protesters shout "baby killer" and "Sodomite" while appearing to point in Buttigieg's direction.

"Remember Sodom and Gomorrah," he yelled over the crowd's chants of "Pete!"

Buttigieg was also confronted by a protester at a smaller event in Fort Dodge, Iowa, earlier on Tuesday after he brought up the subject of same-sex marriage.

"Grandparents, do you want your grandchildren following his example?" the man yelled as audience members booed over him, in a CNN video.

Gesturing toward Buttigieg, he shouted, "God loves us, but he stands for the murder of unborn babies!"

"Coffee after church gets a little rowdy sometimes," Buttigieg quipped after the man was escorted from the room. "That gentleman believes that what he is doing is in line with the will of the creator. I view it differently. We ought to be able to view it differently."

Buttigieg supports abortion rights and said at an event in South Carolina last month, "You’re not free if your reproductive choices are being dictated by male politicians in Washington."

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An Afghanistan veteran and former U.S. Navy intelligence officer who speaks multiple languages, Buttigieg has been drawing crowds and headlines as he surges in early polling in the 2020 Democratic primary.

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He also is a practicing Christian who says there is no reason his sexuality and faith have to be mutually exclusive. Buttigieg has called out Vice President Mike Pence – whom he knows from Pence's time as Indiana governor – for a "religious freedom" law Pence backed that critics said allowed for discrimination against gay people.

"If you have a problem with who I am, your problem is not with me. Your quarrel, sir, is with my creator," he said of Pence's views.

Pence responded by accusing Buttigieg of being "critical of my Christian faith and about me personally."

"He knows better," Pence told CNBC in an interview that aired last week. "He knows me."

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Terry, the heckler at Tuesday's rally, plans to "spend a lot of time" in Iowa hounding Democratic presidential candidates, he told The Hawk Eye.

"My goal is to wake up the Christians who are still voting Democrat and to say to them to put loyalty to God and the babies first," he said, according to The Hawk Eye.

A passionate supporter of President Donald Trump for his appointment of Supreme Court justices Terry believes will lead to the overturn of Roe v. Wade, Terry toured the nation in 2016 in a bus emblazoned with the words "It Is A Sin To Vote For Hillary."

Terry was the founder and leader of Operation Rescue, which came to fame in the 1980s as its members conducted sit-ins and blocked the entrances to abortion clinics. But he and the organization eventually parted ways and the group said in a 2009 statement still posted on its website that "Randall Terry is not affiliated with Operation Rescue and does not speak for this organization in any way."

Operation Rescue said the main reason for its disavowal of its former leader was a statement that it said Terry made appearing to condone the 2009 murder of George Tiller, a Kansas doctor who performed abortions and was fatally shot in a Wichita church.

According to the group, Terry said Tiller's murder, "has the potential to propel us more quickly to our goal."

Contributing: Barbara Rodriguez, Des Moines Register; Brian Lyman, Montgomery Advertiser; and Maureen Groppe, USA TODAY