At least five individuals granted residence in the U.S. through the State Department’s Diversity Visa Program have been tied to terrorism, the White House revealed Tuesday, noting that “hundreds of other foreign nationals” who have entered through the program are currently being investigated for potential links to terrorism.

The decades-old program, which awards green cards to 50,000 prospective immigrants each year, fell under intense scrutiny earlier this month when law enforcement officials confirmed that Sayfullo Saipov, the Uzbek national who is suspected of killing eight individuals during an Oct. 31 terror attack in New York City, entered the country on a permanent residence visa he won through the lottery.