After two weeks of falling costs, national average unleaded petrol prices have jumped 3.7 cents per litre for the first week of March.

Data from the Australian Institute of Petroleum shows the average price across the country (126.0 cents per litre) is at its highest level since the week of January 17 to 24, with all states excluding the Northern Territory and Tasmania experiencing hikes last week.

Adelaide was the hardest hit capital city with prices soaring 7.3 cents per litre to 125.7, while Melbourne was close behind with a weekly change of 6.3 cents per litre for a weekly average of 124.4.

New South Wales and the ACT were in line with the national average, cumulatively adding 3.6 cents per litre to rise to 125.6.

Queensland and Western Australia were not hit as hard this week but remain more expensive overall with weekly averages at 126.6 and 126.4 cents per litre respectively.

Tasmania experienced no change to remain steady at 131.5 while the Northern Territory dropped 0.2 cents for a weekly average of 134.7.

Unleaded was at its most expensive in Tennant Creek where motorists were charged an average of 150.2 cents per litre last week, while the cheapest fuel was on offer in Toowoomba where it was as low as 121.6.

CommSec economist Savanth Sebastian said increasing profit margin pressures on major oil companies and readjustments after the “unsustainable” local price war were behind the recent rises.

“After selling petrol for what was virtually below cost, petrol stations are once again increasing margins in an attempt to remain profitable,” he said.

National average diesel prices rose 0.4 cents per litre last week to 127.1, representing the first increase since the week of January 17 to 24.