Gas prices in Fort Collins have increased 9 cents since last week while prices in Greeley have risen 7 cents, AAA said Wednesday.

The average price for a gallon of gas in Fort Collins increased to $3.70 on Wednesday vs. $3.61 a week ago. In Greeley, gas prices shot up to $3.68 per gallon from $3.61.

Gas prices remained higher in other Colorado cities tracked by AAA.

A gallon of gas in Boulder, Longmont and Colorado Springs cost an average $3.72.

Denver saw a 9-cent increase from $3.62 to $3.71. At $4.03, Vail had the highest average price of gas of places reported on by AAA.

Nationwide, gas prices increased 5 cents to $3.91.
Responding to rising gas prices, Sen. Mark Udall will question panelists at a Senate Energy and Natural Resources Committee hearing Thursday.
Earlier this month, Udall urged Secretary of State Hillary Clinton to find ways to stabilize oil market volatility by pursuing free and competitive trade of petroleum products.
"As gasoline prices go up, the impact reverberates through our entire economy," Udall wrote in a letter to Clinton. "The current disjointed system of energy trade leaves open the possibility of market manipulation and practices that can distort the price of energy."