Fuel prices have risen faster in Northern Ireland than in any other UK region since the beginning of the Iran war.

Analysis of official data shows petrol has jumped by 19% in Northern Ireland since the end of February, and diesel is now 35% more expensive. The rises are among the largest in Europe.

Filling a 50-litre tank cost an average of £75 for petrol and £91 for diesel at the beginning of April. That compares with £63 for petrol and £67 for diesel on 28 February, the day US-Israeli airstrikes on Iran began.

Northern Ireland has had some of the lowest fuel prices in the UK for several years because of tighter competition, reduced dominance of supermarkets and links to Ireland. Although prices remain the lowest in the UK, the gap with other regions has narrowed.

Across the UK, fuel prices continue to rise as the conflict in the Middle East shows no sign of de-escalation. On average, petrol prices have jumped by 16% and diesel by 30% since the start of the war.

Analysis of Eurostat and UK government data shows that only seven other European countries have recorded larger increases in petrol prices than Northern Ireland, with Austrian prices rising by nearly a quarter. The pattern is similar for diesel, with prices jumping by up to 44% in Estonia.

The Guardian’s analysis of the new government scheme to track fuel prices, Fuel Finder, also found that among English regions the north has seen the sharpest increase in petrol prices, with drivers paying an average of 154p a litre, up 17% from 132p a litre on the day war broke out.

Price increases in rural areas are similar to urban but data shows that at least 100 stations in mostly rural parts of England and Scotland are charging between 180p and 210p a litre for petrol.

The average petrol price for 10 major retailers, including supermarkets, has risen sharply. Operators of Shell petrol stations are now charging an average of 158p a litre for standard unleaded petrol, with BP- and Esso-branded petrol stations charging an average of 157p and 155p.

This is an increase of 16% for Esso and Shell and 15% for BP compared with the average price on the day the war broke out, when unleaded petrol was 133p for Esso petrol stations and 136p for BP and Shell petrol stations.

Individual retailers, some of which are fuel companies themselves, control the price of fuel at petrol stations. Prices are based on wholesale costs, local competition and desired profit.

Under the new government scheme, running from the beginning of February, petrol stations must report changes to petrol prices within 30 minutes of altering them. There is a period of three months before petrol stations could get fined if they do not comply with the regulation.

The Guardian analysed data submitted by the stations to the Fuel Finder Scheme so far, as well as historical snapshots from Fuel Costs, which together covers about 70% of the more than 8,300 UK petrol stations, with the rest of the providers either missing the deadline or submitting incomplete data.

Simon Williams, the head of policy at the motoring services company RAC, said: “Drivers hitting the roads this Easter weekend will be faced with some truly eye-watering fuel prices.”

Separate official data analysed by RAC showed that petrol prices have gone up nearly 22p a litre – or 16% – to an average of 154.45p since the beginning of the war.

Williams said: “It [the price of petrol] was last this high at the end of October 2023. The diesel story is even more dramatic, having shot up by almost 9p in the last week alone. It’s now risen by 30% since the end of February, with 43p a litre being added, taking it to an average 185.23p – a price last recorded at the end of November 2022.”