The Homeland Security Department's inspector general is warning that two Secret Service officers were found asleep at their posts.

The new warning, made public Thursday, said fatigue from travel, overtime shifts and long working hours were partly to blame for the incidents in July and August. The officers found asleep, who were not identified, have been referred for disciplinary action. One had worked 60 hours of overtime prior to the incident. The other officer typically worked 12-hour days.

The government's report of the incident was circulated among top officials at the Homeland Security Department and members of Congress.

White House spokesman Eric Schultz declined to discuss the allegations, other than to say that the Secret Service had taken issue with some of the findings in the inspector general's report.