Passengers make their way through a TSA security checkpoint at Baltimore/Washington International Thurgood Marshall Airport in Baltimore. (Kate Patterson for The Washington Post)

The Transportation Security Authority said it had closed a security checkpoint at BWI Marshall Airport Saturday evening because of a shortages of screeners.

In a Twitter message sent Saturday evening, the agency said it “will be exercising a contingency plan” at BWI “due to excessive callouts.”

TSA is responsible for security screening of airline passengers in the United States. TSA screeners are among the federal government employees required to work during the partial shutdown of the federal government. Reports have circulated about possible staffing shortages since the shutdown began.

In its message, TSA said one of its checkpoints at BWI would close at 5:30 p.m.

It recommended that passengers arrive early.

In another news release, TSA said there were more than twice as many unscheduled absences nationally on Friday as last year on the same date.

It said the national rate of unscheduled absences was seven percent, compared with last year’s three percent.

In the release TSA said many employees were saying they could not come to work because of financial limitations.

BWI is one of three airports serving the Washington, D.C., metropolitan area. It is located between Baltimore and Washington.