The national average cost of a gallon of regular unleaded gas hit $4 this week, just a few cents shy of the national record set nearly 14 years ago in July 2008 when it was about $4.11 per gallon. Industry experts said last week that it is likely the U.S. will soon set a new national average gas price record in the wake of Russia’s invasion of Ukraine. The military conflict has raised concerns about potential disruptions to the global oil supply, and prices at the pump have increased in response.

In the last month, national average gas prices have increased by more than 60 cents per gallon, according to American Automobile Association (AAA) data. Last week, AAA spokesperson Andrew Gross told Newsweek that he has “never seen a rise like this before” and said the extent of further price hikes will likely depend upon how the war in Ukraine proceeds.

Gas prices have increased by more than 50 cents per gallon over the last week in several states, with AAA reporting that Rhode Island experienced the largest jump with 58 cents per gallon. In California, where gas prices are often higher than the national average, several statewide average price records have been recorded over the last few weeks, with another set on Monday at $5.343 per gallon.

With price increases expected to continue, state officials issued warnings for consumers to be aware that price gouging is still possible.

“Gas prices fluctuate, but what we have seen this past week is not normal,” Connecticut Attorney General William Tong tweeted on Monday. “Overcharging consumers is unacceptable at any time, but during an abnormal market disruption it is illegal.”

In North Carolina, state Attorney General Josh Stein recently secured a settlement worth more than $20,000 in connection with a gas price gouging incident last year. Stein is keeping an eye on his state’s current gas prices in case any suspected price gouging incidents arise, according to the Charlotte-based news station WBTV.

Last month, Michigan Attorney General Dana Nessel released a video on YouTube warning her state’s residents about unusually high price increases.

“These days, price swings at $0.30 or $0.40 per gallon aren’t unusual,” she said in the video. “But when a gas station charges a price way above the price at similar stations, that could be gas gouging.”

Gas stations in Michigan price gas correctly “most of the time,” she added, “but when a station does try to illegally take advantage of drivers, my office is here to stop them.”

New York Attorney General Letitia James said last week that her office is also taking steps to crack down on gas price gouging.

“New York law prohibits sellers of fuel and other vital and necessary goods from charging unconscionably excessive prices during an abnormal market disruption, including disruptions caused by world conflicts,” she said in a Thursday news release.