Prices have increased about fifteen cents a gallon during the past week.

The price of regular gasoline rose to at least $1.89 per gallon today at most Mountain State gas stations.

The national average is holding at $1.78, although it is expected to increase.

Low test in Grantsville was over $1.90 a gallon yesterday evening.

Speedy Mart in Arnoldsburg was still selling low test at $1.80, but indicated the price would increase with the next load.

The "Y" Mart reportedly had gas at $1.90 cents last night.

State officials and gas marketers say the jump reflects a nationwide increase in crude oil costs, high consumption by American autos and Opec holding production down.