WASHINGTON — A US immigration official told Congress Thursday that it’s hard to monitor applicants’ social media due to “people using foreign alphabets.”

The surprising comment by Leon Rodriguez, director of US Citizenship and Immigration Services, elicited little response from House Oversight Committee members investigating the US visa program following the Dec. 2 San Bernardino, Calif., attacks.

Scrutiny of program security comes after one of the killers, Tashfeen Malik, entered the country legally on a visa despite advocating jihad on Facebook through private messages.