The average price of a gallon of diesel rose 1.2 cents over the past week, according to figures released Monday by the U.S. Department of Energy.

The U.S. Energy Information Administration reported that the average retail on-highway diesel price was $2.943. That's up 30.9 cents per gallon from a year ago. The highest prices were seen in the West Coast region at $3.101, which actually was down three-tenths of a cent from the previous week. The lowest prices in the Gulf Coast region at $2.887, up 1.1 cents per gallon.

Meanwhile, a broken Midwest pipeline sent oil prices higher, as well as gasoline prices in the Midwest. A break in a pipeline about 30 miles from Chicago is part of a pipeline that transports a quarter of the oil imported from Canada to the U.S. Canada is this country's largest foreign oil supplier.

The price for oil futures contracts rose Monday above $77 a barrel on the New York Mercantile Exchange. A weaker dollar also contributed to rising oil prices, since it makes crude oil cheaper for investors using other currencies.

Tom Kloza, chief oil analyst at the Oil Price Information Service, told the Associated Press that the jump in prices is "based mostly on perception." The pipeline break is not a big danger to the country's supplies, since the U.S. right now has the largest stockpiles of oil and petroleum-based fuels on record.