After a six-day outage, the top U.S. fuel pipeline on Thursday moved some of the first millions of gallons of motor fuels after a crippling cyberattack led to fuel shortages across East Coast states.

The Colonial Pipeline, which carries 100 million gallons per day of gasoline, diesel and jet fuel, resumed computer-controlled pumping late Wednesday after adding safety measures. It will take several days for deliveries to fully recover and interruptions are possible, the company said.

The shutdown caused gasoline shortages and emergency declarations from Virginia to Florida, led two refineries to curb production, and had airlines reshuffling some refueling operations.

The pipeline’s restart should bring supplies to some hard-hit areas as soon as Thursday, said U.S. Energy Secretary Jennifer Granholm. She predicted gasoline shortages could end in a couple of days.

“Relief is coming,” added Jeanette McGee, a spokeswoman for motor travel group AAA.

Motorists’ tempers frayed as panic buying led stations to run out even where supplies were available.

The average national gasoline price rose above $3.00 a gallon, the highest since October 2014, the American Automobile Association said, and prices in some areas jumped as much as 11 cents in a day.

Hackers Resurface

As FBI cybersleuths dug into an attack that paralyzed a large part of the U.S. energy infrastructure, the group believed to be responsible said it was publishing data from breaches at three other companies, including an Illinois technology firm.

It was not known how much money the hackers were seeking and the pipeline operator has declined to comment. Colonial has a type of insurance that typically covers ransom payments, three people familiar with the matter told Reuters on Thursday.

To stem fuel shortages, four states and federal regulators relaxed fuel driver restrictions to speed deliveries of fresh supplies. Georgia suspended a sales tax on gasoline until Saturday.

The U.S. also issued a waiver to an undisclosed shipper allowing it to transport gasoline and diesel from the U.S. Gulf coast to East Coast ports on foreign-flagged vessel. The U.S. restricts deliveries between domestic ports to U.S.-built and crewed vessels.

Gulf Coast refiners that move fuel to market on the Colonial Pipeline had cut processing as an alternative pipeline filled to capacity last weekend. Total SE trimmed gasoline production at its Port Arthur, Texas, refinery and Citgo Petroleum pared back at its Lake Charles, Louisiana, plant.

Airlines began refueling planes at their destinations, instead of usual departure points. On Wednesday, Delta Air Lines Chief Executive Ed Bastian said more fuel would be available “hopefully by the end of the week and as long as those predictions come true, hopefully we’ll be OK.”