Federal investigators are looking into multiple reports of vandalism on Southwest Airlines planes.
The findings are disturbing to flyers because the graffiti is being written in Arabic or Arabic-like symbols. It's showing up written in dirt and soot on the outside of planes, according to the FBI.
The markings have reportedly shown up on the underbelly of dozens of planes and according to the a Southwest memo obtained by ABC15 in Phoenix are, “commonly on the engine and/or landing gear."
There was no specific mention of planes at any Bay Area airport, but the markings have been reportedly found across the country.
"This has been going on for several months," Southwest spokesperson Brandy King said in a statement. "We continue to track the impacted fleet, logging when and where the vandalism is taking place."
Southwest Airlines sent out an internal memo saying the markings will be handled as an "internal vandalism issue."
The ABC station in Phoenix broke this story earlier in the week. It had sources that said the markings were likely being done by an employee or group of employees joking around. The sources said it's not uncommon for ground crews to write their names or airport code in the dirt on the planes. But, the workers told ABC15, the recent markings are different.