There is no public evidence to substantiate President Donald Trump’s claim on Tuesday, in the context of a discussion of security at the southern border, that 10 terrorists have been caught recently trying to enter the United States.

Trump’s comments sparked a small tempest on social media, but a recent State Department report showed no terrorist threat on the Mexico border, and Trump’s own administration effectively acknowledges the president may have mischaracterized the statistic.

“People are pouring into our country, including terrorists,” Trump said at a photo-op-turned-policy-debate at the White House, with Vice President Mike Pence and Congress’s top two Democrats, Rep. Nancy Pelosi of California and Sen. Charles E. Schumer of New York. “We captured 10 terrorists over the last very short period of time. Terrorists. These are very serious people. … These are people who were looking to do harm. We need the wall.”

The “source” of the president’s statement, or misstatement, was a Customs and Border Patrol statistic, according to a senior Department of Homeland Security official.

The actual statistic is more nuanced than the president suggested: on average last year, 10 people who are, or are suspected of being, terrorists were blocked each day from entering the United States from multiple locations around the world.

“The data concerns individuals attempting to travel to the United States by air, sea, or land,” the DHS official said. “On average last year, DHS prevented 10 individuals tied to terror — known or suspect terrorists — each day from traveling or attempting to travel to the United States. These are individuals that hit against U.S. terror watchlists. This is in addition to the 17,000 criminals and 3,000 special interest aliens that CBP apprehended at the border last year.”

The DHS statistic is very different from the president’s claim, which many, if not most, listeners inferred was a reference to 10 terrorists being caught trying to enter the United States via its border with Mexico.

On social media, people wondered about the details of his claim and why the administration had not previously touted an apparent security success on the U.S. southern border.

Fully 1.6 million people were on the U.S. government’s terrorist watch list as of last year, according to data published then by the National Counterterrorism Center, which is part of the office of the Director of National Intelligence. The watch list is called the Terrorist Identities Datamart Environment.

Most of the people on that list are merely subject to more rigorous screening than other travelers, according to the Congressional Research Service.

But a minority of the people on the watch list are put on a “no-fly list” and barred from travel. The number of people on the no-fly list is a relatively small fraction of the total on the watch list but is nonetheless a sizable group. News reports in 2014, citing National Counterterrorism Center documents, put the total on the no-fly list at 47,000 people at that time, including 800 Americans.

Some of those on the no-fly list may be terrorists, but many are not. Numerous people have alleged that they have been wrongly put on the lists, often because their names are spelled like someone else’s.

The National Counterterrorism Center’s 2017 document notes that 228,000 names were deleted from the list in the previous six years.