The top US fuel pipeline, which has been disabled by a cyberattack for six days, has sent workers to manually release some stored supplies as fuel shortages across the Southeast worsened and motorists fumed.
A ransomware attack on the Colonial Pipeline last week halted 2.5 million barrels per day of fuel shipments in the most disruptive cyberattack on US energy infrastructure.
The pipeline stretches 8850km from US Gulf Coast oil refineries to consumers in Mid-Atlantic and Southeast states.
Privately owned Colonial Pipeline operator manually opened portions of the line to release needed supplies in Georgia, Maryland, New Jersey and the Carolinas. It has accepted 2 million barrels of fuel to begin a restart that would "substantially" restore operation by week's end, the company said.
The supply crunch, amid panic buying by motorists, has brought long lines and high prices at petrol stations ahead of the Memorial Day holiday weekend at the end of this month, which traditionally marks the start of the peak summer driving season.
Nearly a third of petrol stations in metro Atlanta and in Raleigh and Charlotte, North Carolina, were without fuel, tracking firm GasBuddy said. The average price for regular petrol rose to $US2.99 a gallon, the highest since 2014.
"This place is dead closed," said Charles Staples, a 31-year-old banker, after circling rows of shut fuel pumps in his Volvo at an Atlanta station. "I heard about the thing, but I just thought they'd be long lines or something."
In Raleigh, North Carolina, the last few stores with petrol were those along major thoroughfares, said Todd Sloan, a general contractor. "Those that have fuel have very long lines," he said.
Four southeast states - Florida, North Carolina, Virginia and Georgia - joined federal regulators in relaxing driver and fuel restrictions to speed deliveries of supplies. Georgia suspended sales tax on petrol until Saturday.
The FBI has accused a shadowy criminal gang called DarkSide of the ransomware attack. DarkSide is believed to be based in Russia or Eastern Europe.
Russia's Embassy in the United States rejected speculation that Moscow was behind the attack. President Joe Biden on Monday said there was no evidence so far that Russia was responsible.
It is unknown how much money the hackers are seeking, and Colonial has not commented on whether it would pay.
Gulf Coast refiners that rely on the Colonial pipeline to move fuel to market have cut processing.
Australian Associated Press