Fears that the shutdown of a major fuel pipeline network could cause a gasoline shortage led to some panic buying and prompted US regulators on Tuesday to temporarily suspend clean fuel requirements in three eastern states and the nation's capital.
While it remained unclear the degree to which supplies would be affected, drivers lined up to fill their tanks at gas stations in the Southeast, with some carrying extra containers amid fears of fuel scarcity.
A ransomware attack on Friday on Colonial Pipeline forced the company to close its entire network, but government officials called for calm on Tuesday and said the situation is only temporary.
Colonial Pipeline, the operator of the largest fuel conduit system in the United States, sends gasoline and jet fuel from the Gulf Coast of Texas to the populous East Coast through 8,850 kilometers of ducts that serve 50 million consumers.
The company said it expects to have the pipeline network fully up and running by the end of the week.
US Energy Secretary Jennifer Granholm said on Tuesday that some areas "may feel a supply crunch, as Colonial fully resumes".
However, "there should be no cause for hoarding gasoline, especially in the light of the fact that the pipeline should be substantially operational by the end of this week and over the weekend", she told reporters at the White House.