Washington area motorists swarmed gas stations yesterday after hearing false rumors of impending shutdowns throughout Maryland and Virginia, as fuel shortages tightened and prices spiked again.

Virginia Gov. Mark R. Warner (D) and Maryland Gov. Robert L. Ehrlich Jr. (R) acted quickly to quash the rumors. A Baltimore Police Department helicopter circled over some gas stations in the area yesterday with loudspeakers assuring drivers in line that supplies were adequate.

"There's plenty of gas. There's no need to clog the streets," said a Baltimore police spokeswoman, Officer Nicole Monroe. "Any time you have that many people, and they're upset and tensions are high, there are safety concerns."

Warner sought late in the day to further allay consumers' fears by announcing that flows of gasoline to the region had significantly improved through pipelines disrupted by Hurricane Katrina.

He also declared a state of emergency yesterday to activate the state's anti-gouging law after a gas station in Centreville was cited for charging $5.80.

Maryland Attorney General J. Joseph Curran Jr. (D) also announced yesterday he would conduct an inquiry into rising gas prices with his counterparts across the country. "Like my fellow Marylanders, I am wondering why gasoline that was already bought and paid for by stations here has suddenly skyrocketed in price," Curran said. "This a national problem, and this is going to be a multi-state inquiry."

Travelers across the country said they had canceled or cut short vacations this weekend, fearing shortages and escalating prices. Georgia Gov. Sonny Perdue (R) announced he would temporarily eliminate the state's gas taxes through the end of the month, bringing relief of about 15 cents per gallon to residents. AAA and even gasoline companies asked travelers to stay home this weekend unless they absolutely had to be on the road and urged them to cut short their trips.

AAA Mid-Atlantic spokesman John B. Townsend II said average gas prices in the Washington area jumped 16 cents yesterday, to a new high of $2.89, as more stations began to feel the pinch of dwindling supplies. In Virginia, prices rose 20 cents, to $2.82, Townsend said, while in Maryland prices climbed 19 cents, to $2.92. Prices in the District rose 10 cents, to $2.73, he said. Although a growing number of gas stations closed in the area yesterday, the Washington region remains in relatively better shape than many other places, such as North Carolina, Georgia and Louisiana, where customers have had to wait in line for as long as two hours. Officials urged travelers to conserve gas this weekend and tried to calm residents with news that the hurricane-damaged pipelines and refineries are slowly getting back up and running.

"The supply situation is dire," said Susan Broughton, spokeswoman for the Society of Independent Gasoline Marketers of America, which represents one-third of the nation's retailers. Broughton urged drivers to cut their trips short this weekend because a number of gas stations in North Carolina, Georgia and Florida have run out. "No one wants to give a sense of panic, but it's common sense that if you don't need to travel, then don't."

Exxon Mobil Corp. said in a statement that demand at its stations has nearly doubled in the past several days.

Lines began forming at stations in the Washington area yesterday morning. By the afternoon, rumors of region-wide shutdowns began to spread, and people rushed to their cars and headed to the nearest gas station. Residents in Maryland said they heard that all the state's gas stations would close by 4 p.m. In Virginia and the District, drivers asked station managers whether all stations would be closed on Labor Day. All the rumors turned out to be false.

Jessica Walters got the call on her cell phone yesterday afternoon from a girlfriend who had heard the rumors from her friend who works for the federal government. Walters, who works at a law firm in Columbia, hopped in her Isuzu Trooper and went to a nearby Exxon on her lunch break. It was so crowded that she couldn't turn in to the station.

"People were chaotic," she said. "I feel like I'm scared of something. My heart is beating so fast. I'm like, 'What's wrong with me?' "

At a station near Johns Hopkins Hospital in Baltimore where drivers had heard the same rumors, three city policemen tried to control the crowd. "They were directing traffic and telling people 'Okay, it's your turn. Now, sir, it's your turn. No, you can't fill up those three containers,' " said Diana Pillas, who works at Hopkins. "The policemen kept saying 'Folks, it's a rumor!' but nobody was listening."

Although it is unclear how the rumors got started, the first panicked calls came into Ehrlich's office shortly before 1 p.m. yesterday, asking if he had ordered all gas stations to close. By 3:15, the governor's office was fielding calls every minute. A spokeswoman did several radio interviews to try to debunk the rumors, and the governor issued a short news statement, but it did not seem to help. Ehrlich finally decided to hold a news conference by late afternoon to address the rumors himself.

"There is not anywhere near a crisis situation in Maryland," Ehrlich said. "That's just a fact."

Gas station managers reported isolated instances of customers trying to hoard gasoline by filling up cans. Mostly they heard complaints, they said. District police said they were monitoring gas stations and traffic nearby in case fights broke out.

"People are buying more than they were yesterday, and it's 50 cents more a gallon," said station manager Inderjet Rana, of the Crown gas station on Edsall Road in Alexandria, where gas was $3.59 for regular. "Thirty dollars, forty, fifty, they have no choice. . . . I say, 'It will be down, but I don't know when.' "

A Chevron station in Rosslyn hiked its prices up to $3.59 yesterday -- a 20-cent jump -- and tried to explain to customers in a note on the door "Please be advised, due to Hurricane Katrina . . . we do not have enough petroleum product to keep all gas stations supplied."

"Everybody complains. They want to fight with me," said Abraham Agazh, an employee at the Saint Rosslyn's Chevron.

Derrick Wood, who was waiting in his parked blue Volvo at the Hess station at Rhode Island and New Jersey avenues in the District, said the escalating gas prices had forced him to cancel a visit to his family in New Jersey.

"Right now, it's just not worth it," Wood said. With no end in sight to the almost daily price hikes, Wood said he feared that regular would hit $5 a gallon. "I've thought about riding a bike to work," he said.

Staff writers Fern Shen, Matthew Mosk, Mark Chediak, Dina ElBoghdady, Chris L. Jenkins and Susan DeFord contributed to this report.