International travelers were waiting in long entry lines at some of the nation's busiest airports Friday because of a U.S. Customs and Border Protection computer outage, authorities said.

By early evening Friday, the CBP tweeted, "Affected systems are coming back online and travelers are being processed."

"There is no indication the disruption was malicious in nature at this time," the agency said.

A CBP official said in an earlier statement that the agency was "experiencing a temporary outage with its processing systems at various air ports of entry and is taking immediate action to address the technology disruption."

The outage affected New York's John F. Kennedy Airport, Los Angeles International Airport and Chicago's O'Hare International Airport, among others. Images on social media showed travelers jammed into terminals at JFK and O'Hare as they awaited admittance to the United States.

"Customs is experiencing a system shutdown nationwide," JFK tweeted Friday afternoon. "They are processing passengers manually until the system comes back online. Thanks for your patience."

Frederick Badlissi, a spokesman for LAX, said the airport was also impacted and that "we're advising travelers to check with their airlines" about possible wait times.

The CBP official said the agency was "using alternative procedures until systems are back online."

"CBP officers are working to process travelers as quickly as possible while maintaining the highest levels of security," the official said.

The snafu comes as some airports, including Atlanta's Hartfield-Jackson, have complained that U.S. Homeland Security has shifted some CBP personnel to the U.S.-Mexico border to bolster security there, resulting in longer wait times for international travelers.