President Trump on Thursday again cited a story about the late U.S. Army Gen. John J. Pershing dipping bullets in pigs’ blood to deter Islamic attacks that has been dismissed by historians as apocryphal.

“Study what General Pershing of the United States did to terrorists when caught,” the president tweeted. “There was no more Radical Islamic Terror for 35 years!”

Trump’s tweet on Thursday followed the attack in Barcelona, Spain, where a car plowed into a crowd, killing and injuring pedestrians.

The general story is one Trump told – and was criticized for – during the presidential race.

Speaking of Pershing’s role after the Philippine-American War of 1899-1902, Trump praised the general during a rally in North Charleston, S.C., in February of last year.

“They were having terrorism problems, just like we do,” Trump said at the time.

BARCELONA TERROR ATTACK

The president went on to say Pershing ordered his men to dip bullets in the blood of pigs, since pork is forbidden in Islam.

“He lined up the 50 people, and they shot 49 of those people,” Trump said. “And the 50th person, he said: 'You go back to your people, and you tell them what happened.' And for 25 years, there wasn’t a problem. Okay? Twenty-five years, there wasn’t a problem.”

During the campaign, the fact-checking website Politifact referred to the story as a “dubious legend.”

"This story is a fabrication and has long been discredited," Brian McAllister Linn, a Texas A&M University, told Politifact. "I am amazed it is still making the rounds."

While historians dismiss the tale of dipping bullets in pigs’ blood, Pershing did tell a story about using pigs to deter terrorist attackers in his memoir.

“The bodies were publicly buried in the same grave with a dead pig,” Pershing wrote. “It was not pleasant to have to take such measures, but the prospect of going to hell instead of heaven sometimes deterred the would-be assassins.”

