CALGARY - Soaring gasoline prices in Calgary and Edmonton have pushed the national average to a five-year high, according to an online price monitoring firm.

Dan McTeague of GasBuddy.com says the national average price for regular gasoline was 136.0 cents per litre on Thursday, up from 105.2 cents on the same date last year and closing in on the previous high of 139.1 cents in June 2013.

According to the website's live price counter, prices in Calgary averaged 138.2 cents per litre on Thursday morning, up 11.6 cents from last week's average and 43.8 cents from the same date a year ago.

Edmonton prices were at 136.2 cents per litre, up 13 cents from last week and 47.8 cents from 12 months ago.

McTeague says the biggest cause of this week's surge in Alberta prices was "gas bar shenanigans," as retailers who hadn't passed on recent increases in wholesale prices decided to catch up all at once.

He doesn't expect the increases to stick, pointing out some stations in Edmonton are already retreating.