Raleigh, N.C. — Two more gas stations must refund money to drivers in an ongoing price-gouging investigation.

North Carolina Attorney General Roy Cooper announced Friday that The Corner Market in Jefferson and Citgo in Old Fort overcharged customers on Sept. 12 and 13 when they marked up gas prices in anticipation of Hurricane Ike.

The Corner Market, at 1462 U.S. Highway 221 North, raised prices from $3.69 to $5.29 per gallon, overcharging consumers by more than $1,600 on Sept. 12, according to the investigation. The station agreed to refund up to $1.69 per gallon to customers.

The Old Fort Citgo overcharged by almost $2,000 on Sept. 12 and 13 after raising prices from $3.99 to $4.99 per gallon. The investigation also found evidence of gouging on diesel prices at the station.

Both companies will pay a $5,000 fine.

Drivers who paid by credit card will see a refund on their card statement. Those who paid cash can present a receipt to get their refund

The owners of a Fayetteville gas station and five stations in Cherokee and Clay counties agreed earlier this month to pay refunds. The owner of a Montgomery County station faces a lawsuit alleging he raised prices too fast in the wake of Hurricane Ike.

The attorney general issued a subpoena Friday for the owner of 10 Circle K stores in Charlotte on reports that some Circle Ks charged as much as $5.29 a gallon in the days before and after the storm made landfall along the Gulf coast..

After pump prices skyrocketed amid fears that the storm would cripple refining capacity and create gas shortages, thousands of drivers complained to the Consumer Protection Division in Cooper's office that prices went up too high and too fast.

Across the state, owners of 36 gas stations have been questioned about their wholesale prices and the retail prices they charged. Cooper said stations could not be cited under North Carolina's price-gouging law if they were simply passing along their higher prices.