Prices at Washington area gas pumps jumped yesterday -- by 88 cents a gallon at one station -- as the effects of Hurricane Katrina swept into the region.

With prices in some places well above $3 a gallon for regular gasoline, attorneys general in Virginia and Maryland said they were monitoring complaints from residents about price gouging. Maryland Attorney General J. Joseph Curran Jr. said his office received several reports of sharp price increases. Motorists told Curran of increases as high as $1.05 a gallon.

The AAA auto club said drivers should not panic and rush to the pumps, despite reports that gas prices could reach $4 a gallon before refineries and pipelines hit by the hurricane in the Gulf of Mexico are back in operation.

Motorists were confused that the price increases varied widely, from pennies to a dollar. The variations were due to how stations buy their gasoline. Most branded stations, such as Exxon and Shell, have contracts that lock in prices over extended periods, allowing them to weather fluctuations in the market caused by disasters such as Hurricane Katrina.

Independent stations, which usually purchase gas on the spot market, suffer from daily price swings and are more likely to boost their prices significantly during chaotic events. Gasoline futures prices have climbed about 35 percent since Friday.

"There's a lot of anxiety among traders," said Rayola Dougher, manager of energy market issues at the American Petroleum Institute in Washington. She said it was too early to tell how long prices would continue to rise and whether they would reach $4 a gallon because it is unclear how soon normal operations will resume at the refineries and pipelines in the Louisiana area. "We should expect to see tremendous variation" in gas prices, she said.

Woodbridge resident Tom Yancoskie said his corner gas station on Prince William Parkway was selling regular at $2.91 a gallon yesterday morning, 40 cents more than on the night before.

"I thought maybe I misread it. . . . My eyes were blurry," said Yancoskie, who has already traded in his Chevrolet Silverado for a more fuel-efficient Toyota Corolla to save money on gas. "Then my wife e-mailed me and said, 'Is that a misprint?' That's the biggest hike I've ever seen."

A gas station called Lowest Price in Seat Pleasant, Md., had a hard time justifying its name yesterday. Motorists were startled to see prices rise 88 cents throughout the day, to $3.49 a gallon for regular. "Is that a mistake?" asked James Tibbs, looking at the sign.

One woman took her $15 back from the clerk before pumping any gas after she noticed the price. Another customer drove in, popped off his gas cap, looked at the price, then sped away in his Cadillac Seville, forgetting to replace the cap.

The average price for a gallon of regular gas was $2.75 in the District yesterday. In the Manassas area it was $2.58, and in Bethesda it was $2.82, with a high of $3.16 a gallon at some stations.

Prices varied yesterday even on opposite corners. In Hyattsville, Md., drivers lined up at the Exxon station at Queens Chapel and Chillum roads, while across the street, the Crown gas station was deserted. Exxon's price of $2.84 a gallon was 11 cents less than Crown's.

"In four days I have spent $50 on gas for my car," said Gbade Tokan, who runs a business driving people around in his van. He looked up at the price at Exxon, noting that it was more than 20 cents less two days ago. "It has cost me all of my savings just to buy gas every day," he said.

On average, drivers in the Washington area are paying about $10 more to fill up their tank this year than last year, according to AAA.

Jocelyn Golphin said the price seemed to be going up by the hour. "This is ridiculous," she said, fueling her car at the Exxon station. "It was $2.74 this morning. They don't have to go as high as they are."

Attorneys general in Virginia and Maryland lack the power to prosecute price gougers but can refer suspected incidents to federal agencies. Curran asked the Federal Trade Commission to investigate.

"We've asked them to determine whether Katrina is the cause of the spike or are there other unrelated causes that are producing this," Curran said. "And if so, to give a report so the public can be aware."

The Washington area has fared better than areas closer to the hurricane. In parts of Louisiana, Mississippi and even Georgia, gas stations ran out of fuel.

"There's no gas. We don't have any as of one hour ago," Hoa Thai, who works at First Stop gas station in Mobile, Ala., said yesterday afternoon. The station was selling regular unleaded for $2.43, she said. She was not sure when the station would get more gas.

Prices varied elsewhere. Just outside Shreveport, La., a Circle K sold regular gas for $2.41 a gallon, while half a block away at a Brookshire's, it was going for $2.79.

In North Carolina, Gov. Michael F. Easley suspended all nonessential state government travel and urged residents to carpool whenever possible, noting that 90 percent of the state's gas comes from two pipelines have been shut down since the hurricane struck. "We are not out of gas, but we are running low," he said.

AAA backed off its prediction just days ago that half a million people from the region would drive 50 miles or more over Labor Day weekend. Instead, the organization said drivers should conserve gas and ride the Metro when possible.

"If everyone goes out and buys gas, it creates a panic," said AAA Mid-Atlantic spokesman John Barrett Townsend II. "If people see others waiting in long lines in Louisiana on television, that could spread" and put more pressure on the already-limited supply of gasoline. "Whatever happens, we'll get through this. It depends on how long the infrastructure is down. It could be a week or two weeks."

The only relief in sight, Townsend said, was the expected drop in demand for gas after Labor Day when road travel declines.

Staff writer Dana Hedgpeth in Louisiana contributed to this report.

Martin Wagner of Fredericksburg ran out of gas yesterday at a station on Route 15 between Leesburg and Aldie. Staying full has its price, too.