A "potentially widespread" fuel contamination at gas stations along Florida's Gulf Coast could cause car engines and power generators to stop working just as Tropical Storm Idalia approaches the area.

The contamination was caused by "human error" at the Port of Tampa, according to a news alert from the Florida Department of Agriculture and Consumer Services.

The affected gasoline and diesel, supplied by Citgo, may have been sold at nearly 30 stations after 10 a.m. ET on Saturday, mostly along the Florida coast from the Tampa Bay region to Fort Myers.

Using the fuel could cause engine damage or stop a vehicle or generator from operating entirely, FDACS warned.

Speaking at a press briefing Sunday, Florida Gov. Ron DeSantis said the potentially hazardous situation was caused by a simple mix-up.

"Basically it was just human error — they just put diesel in tanks that were supposed to be regular gas," DeSantis said, according to a report from NPR member station WUSF.

"If you have a tank of gas and it's 90% regular and 10% diesel, the dilution probably may not ruin your car," he continued. "But, I mean, if you put a whole tank of diesel, that's going to be a major, major problem."

Officials are still investigating how widespread the problem is.

The impacted stations all have been asked to stop selling gas until the fuel can be replaced and the tanks that were used can be cleaned. BJ's Wholesale, 7-Eleven and Handy Foods were some of the impacted stores.

Florida's Division of Emergency Management has also waived size, weight and hour restrictions for transporting gas and diesel in the state to ensure consumers could have access to fuel as quickly as possible.

Forecasters warn Tropical Storm Idalia could become a major hurricane in the Gulf of Mexico as it approaches the Florida coast late Tuesday.

As of Monday morning 33 counties along the coast from Panama City to Fort Myers were under an emergency declaration. Authorities encouraged residents with vehicles to keep their gas tanks at least half-full should the need for evacuation orders arise.