Republican front-runner Donald Trump tweeted a response to an al-Shabab recruitment video featuring the presidential candidate’s anti-Muslim remarks, saying the Somali terrorist group is “not ISIS” — the Islamic terrorist organization also known as the Islamic State Group. During the last Democratic presidential debate, Democratic front-runner Hillary Clinton said ISIS was using Trump’s remarks in recruitment videos. There has been no evidence such videos exist.

“Al-Shabbab [sic], not ISIS, just made a video on me,” Trump tweeted Sunday. “They all will as front-runner & if I speak against them, which I must. Hillary lied!”

SITE Monitoring reported the existence of the al-Shabab video Saturday. It shows Trump saying Muslims should not be allowed into the United States and then shows a clip of radical U.S.-born cleric Anwar al-Awlaki, who was killed in a U.S. drone strike in Yemen, saying Muslims in the United States will be forced to choose between leaving and fighting the West at home.

Al-Shabab seeks to overthrow the Western-backed Somali government and replace it with its version of Shariah law. The group also has links to al Qaeda.

"Look, there's a problem," Trump said on CBS's "Face the Nation." "I bring it up. Other people have called me and say, 'You have guts to bring it up because frankly, it's true, but nobody wants to get involved. Now people are getting involved.

"People that are on different persuasions than me right now, John, are saying, you know maybe Trump isn't wrong. We want to examine it."

Trump brushed off concern about being used in the recruitment video, saying: "They use other people, too. What am I going to do? I have to say what I have to say. And you [know] what I have to say? There's a problem. We have to find out what is a problem. And we have to solve that problem."

Trump has raised outrage — as well as support — with over-the-top remarks on a variety of subjects. In addition to suggesting the U.S. block Muslims' entry into the country, the real estate mogul also has claimed he saw television clips of hundreds of Muslims celebrating the attacks on Sept. 11, 2001, in Jersey City, New Jersey. No such videos exist, although there were celebrations elsewhere in the world.

Trump is leading the rest of the Republican field in various polls. The RealClearPolitics average has him ahead of his nearest rival, Sen. Ted Cruz of Texas, nationally by more than 15 points, 35 percent versus 19.5 percent. In Iowa, where the first-in-the-nation caucuses occur Feb. 1, Cruz leads Trump by less than 4 points, 31 percent versus 27.4 percent. Trump leads Cruz by 13 points in New Hampshire, which holds its first-in-the-nation primary Feb. 9.