The FBI is reportedly scrambling to find more than a dozen Uzbek nationals who sought asylum in the US earlier this year, after intelligence officers discovered they traveled to the southern border with the help of a smuggler who has ties to ISIS.

Officials are working to “identify and assess” all of the individuals who gained entry into the country, National Security Council spokesman Adrienne Watson told CNN.

They are also scrutinizing a number of migrants as possible criminal threats, two unnamed federal officials told the news network. But authorities say no specific ISIS plot has been identified.