U.S. Customs and Border Protection encountered only six immigrants on the U.S.-Mexico border whose names were in a federal database of known or suspected terrorists, contradicting earlier White House claims that nearly 4,000 suspected terrorists were stopped at the country’s southern border.

The disclosure, made by Secretary of Homeland Security Kirstjen Nielsen Monday and first reported by NBC News, concerned only the first half of 2018. Of 41 people stopped at the U.S.-Mexico border by the CBP in that period, 35 were U.S. citizens or lawful permanent residents, with the other six classified as non-residents.

By contrast, the CBP encountered 91 people at the U.S.-Canada border whose names were on the federal list, with 41 of them non-U.S. citizens or residents, NBC said.

On Friday, White House press secretary Sarah Sanders, said that CBP stopped nearly 4,000 known or suspected terrorists from crossing the southern border in 2018. Fact-checks of Sanders’ statement showed that the 4,000 figure applied to 2017, not 2018, and included stops made by DHS officials around the globe, with the vast majority of them occurring at airports.

Sanders appeared on Fox News Sunday and mentioned again the 4,000 known or suspected terrorists figure. When Fox News host Chris Wallace challenged her assertion and mentioned that most of the stops happened at airports, Sanders acknowledged that “they’re coming in a number of ways.”

Wallace then countered, “The State Department says there hasn’t been any terrorists that they’ve found coming across the southern border with Mexico.”