Los Angeles, California - The websites of several major US airports were inaccessible on Monday after a targeted attack by a pro-Russia hacking group.

Killnet listed 14 websites, including those of LaGuardia in Queens, New Los Angeles' LAX, and Atlanta's Hartsfield-Jackson International Airport, among the US airports that it was targeting, according to reports.

A statement from LAX confirmed that portions of the public-facing website were disrupted. There were no disruptions to operations or airport systems. By Monday evening, the website appeared to be operating normally. The cause is under investigation. LAX notified the Transportation Security Administration and the FBI about the incident.

Killnet hackers previously released a video supporting Russia and claimed credit for implementing a DDoS attack, a "distributed denial of service" attack in which servers are flooded with web traffic to knock websites offline, against a US airport in March in retaliation for US support for Ukraine, according to a federal cybersecurity advisory.

Henry Harteveldt, a travel industry analyst with Atmosphere Research Group, said an attack on the LAX website is unlikely to affect airline operations, since every airline operates its own website.

But he added that he's concerned about what could happen if the group attacks other parts of LAX's infrastructure.

"Depending on what would be attacked, it could possibly affect airlines, terminal operations, concession operators, or others," he said in an email.

"The attack on the LAX website should not be dismissed as trivial or inconsequential, unless and until it is proven to be so."