The national average for gas prices jumped 6 cents on the week to $2.96 and is poised to rise even higher in some areas because of Friday’s cyberattack against Colonial Pipeline Co., according to the American Automobile Association.

Colonial Pipeline operates a 5,500-mile system taking fuel from the refineries of the Gulf Coast to the New York metro area.

The pipeline transports more than 100 million gallons a day, or roughly 45% of fuel consumed on the East Coast. It delivers gasoline, diesel, jet fuel and heating oil and serves U.S. military facilities.

“This shutdown will have implications on both gasoline supply and prices, but the impact will vary regionally,” AAA spokesperson Jeanette McGee said in a statement. “Areas including Mississippi, Tennessee and the East Coast from Georgia into Delaware are most likely to experience limited fuel availability and price increases, as early as this week. These states may see prices increase 3 to 7 cents this week.”

An increase of three more cents would make the national average the most expensive since November 2014, when average gas prices were $2.99 and higher.

According to AAA, the nation’s top 10 largest weekly increases were in Michigan (up 15 cents), Kentucky (12 cents), Florida (10 cents), Delaware (10 cents), Indiana (10 cents), West Virginia (9 cents), Utah (9 cents), Texas (9 cents), New Jersey (8 cents) and Pennsylvania (7 cents).

The 10 least expensive markets were Mississippi ($2.61), Louisiana ($2.64), Texas ($2.66), South Carolina ($2.67), Alabama ($2.68), Oklahoma ($2.70), Missouri ($2.71), Tennessee ($2.71), Arkansas ($2.72) and North Carolina ($2.73).

The White House has established an interagency working group to help resolve the issue and the Department of Transportation is offering motor carriers and drivers transporting gasoline, diesel, jet fuel and other refined petroleum products more flexibility through a temporary hours of service exemption.

While there is a sufficient gas supply in the United States of 235.8 million barrels and other pipeline systems in place to help ease the strain of the disruption, AAA warns that these efforts will not resolve the issues caused by the pipeline disruption. Once the Colonial system is back up and running, there could be residual delays as it takes about 15 to 18 days for fuel to flow from Texas to New York.

AAA is monitoring the Colonial Pipeline situation and is urging against panic buying of gasoline.

Motorists can conserve fuel by planning ahead to accomplish multiple errands in one trip, avoid high traffic times of day, use their most fuel-efficient model vehicles owned, remove unnecessary and bulky items from their car, and minimize air conditioning use.

Colonial Pipeline said in its latest update it was developing a system restart plan.

“While our mainlines (Lines 1, 2, 3 and 4) remain offline, some smaller lateral lines between terminals and delivery points are now operational,” the company said. “We are in the process of restoring service to other laterals and will bring our full system back online only when we believe it is safe to do so, and in full compliance with the approval of all federal regulations.”

According to Colonial, the attack involved ransomware, where an attacker seizes control of computer systems to demand a payoff. However, the company did not say what was demanded or whether a ransom has been paid.

The cyberattack is currently being investigated by FBI, Department of Energy (DOE) and  Cybersecurity and Infrastructure Security Agency (CISA).