Washington (CNN) -- The U.S. Secret Service has made some staffing and rule changes in the wake of recent incidents involving agents and alcohol in Amsterdam and in the Florida Keys.
The changes were first reported by the Washington Post.
Secret Service agents in the Special Operations Division are now barred from drinking alcohol within 12 hours of duty and 24 hours before the President arrives on location for a trip, a U.S. Secret Service official with knowledge of the rule change told CNN on Tuesday.
"The alcohol consumption directive ... was implemented by a special agent in charge and was limited to the division and employees under his supervision," said the official, who spoke on the condition of anonymity.
Secret Service Director Julia Pierson was called to Capitol Hill last week to explain recent misconduct by her agents.
In the latest incidents, three agents who were part of the President's advance security detail were sent home from the Netherlands after one of them was found passed out in a hotel hallway after a night of drinking.
Also, a Secret Service officer in Florida was involved in a traffic accident and alcohol use was suspected.
"These are isolated incidents of misconduct and we're working every day to correct our behavior," Pierson told reporters on Tuesday after leaving a closed meeting with top senators on the Homeland Security and Governmental Affairs Committee.
"We're human and we make mistakes," she said.
Pierson "maintains a zero tolerance policy regarding incidents of misconduct and continues to evaluate the best human capital practices and policies for the workforce," said U.S. Secret Service spokesman George Ogilvie, by way of announcing changes.
He said personnel were being reassigned "as a result of staffing rotations and as a result of assessments made after two recent incidents of misconduct. These assessments of the Special Operations Division include personnel, staffing, scheduling practices, etc."
The spokesman added that the Secret Service has not implemented or changed any agency-wide policies regarding alcohol.
"Policies that would affect the entire workforce are currently under review by leadership," Ogilvie said in a statement.
CNN's Ted Barrett contributed to this report.