AUGUSTA — As a deep freeze blankets Maine, state energy officials say heating oil prices continue to go up.

According to today’s weekly survey by the Governor’s Office of Energy Independence and Security, the average cash price for heating oil is $3.23 a gallon. That’s 5 cents higher than a week ago.

Northern Maine has the highest prices, while southern Maine has the lowest.

Director John Kerry said frigid temperatures in the Northeast have increased demand for heating fuels, helping drive up prices.

Kerosene in the past week has gone up 7 cents a gallon, to $3.61. Propane has climbed 4 cents a gallon, to $2.88.