An outage affecting the Customs and Border Protection's computer systems left international travelers waiting in long lines at airports throughout the country Monday night.
The outage affected airports including JFK, San Francisco and Denver, as international travelers arrived from holiday travels on New Year's Day.
CBP said "there is no indication the service disruption was malicious in nature." It said that all airports were back online after the outage lasted from 7:30 p.m. to about 9:30 p.m. ET.
Passengers who landed during those hours stood in long, snaking lines at the international arrivals area, trying to get through passport control.
CBP said it "took immediate action to address the technology disruption."
"CBP officers continued to process international travelers using alternative procedures at affected airports. Travelers at some ports of entry experienced longer than usual wait times as CBP officers processed travelers as quickly as possible while maintaining the highest levels of security," it said in a statement.
The agency said it had access to the national security-related databases during the outage.
Several airports, including JFK International and the Dallas Fort Worth International acknowledged the delays on Twitter.