PHILADELPHIA (CBS) — We’re learning more about the five planes flying in formation Monday night over the Philadelphia and South Jersey area.

A spokesperson for the FAA told KYW Newsradio on Monday that the group of jets flying in formation was a “military operation.”

FAA: Jets Flying In Formation Over Philly Was ‘Military Operation’

What does that mean exactly?

We now know they were Saudi Arabian aircraft headed back home by way of Joint Base McGuire-Dix-Lakehurst in Burlington County, according to officials at the base.

A Joint Base McGuire-Dix-Lakehurst spokeswoman says they were four fighter jets and a refueling tanker.

She says they were making a planned stop at the base after military exercises at Nellis Air Force Base in Nevada.

These type of exercises are called ‘Red Flag’ air combat training, which includes crews from the US and its allies.

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KYW Newsradio received several tip calls and emails about the evening fly-over.

Saw it over Oaks Pa. Could not tell if commercial or Air Force One? — Templefan! (@HolcS777) August 28, 2017