NEW : Two U.S. lawmakers demand answers about their status . NEW : Rep. McCaul says it shows a `` serious hole '' in national security . Comment: The memo went out earlier this week as part of an effort to reform the student visa system , said the official , who spoke on condition of anonymity . Two friends of the Boston bombing suspect reportedly overstayed their visas .
NEW : Two U.S. lawmakers demand answers about their status . NEW : Rep. McCaul says it shows a `` serious hole '' in national security . Comment: Two friends of the Boston bombing suspect reportedly overstayed their visas .