UPDATE: PHL Bomb Threat 1 of 5 Across Country

A hoax bomb threat against a flight that landed at Philadelphia International Airport was one of at least five warnings made against planes Tuesday morning, according to NBC News.

Threats to other flights included:

• Delta Flight 55, from Los Angeles to Atlanta;
• United Flight 995, from San Francisco to Chicago O’Hare;
• Volaris Flight 939, from Portland, Oregon,to Guadalajara, Mexico; and
• Korean Air Flight 23 from Seoul to San Francisco.

Government officials have deemed the threats not credible.

Philadelphia police and firefighters boarded the US Airways plane that arrived from San Diego and found the threat was a hoax, police told NBC Philadelphia.

The 93 passengers on an Airbus 320 were removed from the plane at 7 a.m., and K-9 units were seen boarding the aircraft, 6-ABC reports.

There are no reports of injuries. An investigation into the threatening phone call is underway.

This post will be updated as more information is available.