After petrol, diesel is now at almost Rs 100 per litre mark in Rajasthan as oil firms raised fuel prices yet again on Friday.

Petrol price was hiked by 29 paise per litre and diesel by 28 paise, according to a price notification of state-owned fuel retailers.

The hike -- the 22nd since May 4 -- took fuel prices across the country to historic highs.

Petrol is retailing above the Rs 100 per litre mark in six states and union territories -- Rajasthan, Madhya Pradesh, Maharashtra, Andhra Pradesh, Telangana and Ladakh.

In Delhi, petrol hit an all-time high of Rs 95.85 a litre, while diesel is now priced at Rs 86.75 per litre.

Fuel prices differ from state to state depending on the incidence of local taxes such as VAT and freight charges.

Sri Ganganagar district of Rajasthan near the India-Pakistan border has the costliest fuel in the country -- petrol is priced at Rs 106.94 a litre and diesel at Rs 99.80. This small town was the first in the country to see petrol price hit Rs 100 a litre mark in mid-February. Premium or additive laced petrol in the town sells for Rs 110.22 a litre and same grade diesel at Rs 103.47.

Rajasthan levies the highest VAT on petrol and diesel in the country, followed by Madhya Pradesh, Maharashtra, Andhra Pradesh and Telangana.

Mumbai on May 29 became the first metro in the country where petrol was being sold at over Rs 100 a litre. Petrol now costs Rs 102.04 a litre in the city and diesel comes for Rs 94.15.

The hike on Friday was the 22nd increase in prices since May 4, when state-owned oil firms ended an 18-day hiatus in rate revision they observed during assembly elections in states like West Bengal.

In 22 increases, petrol price has risen by Rs 5.45 per litre and diesel by Rs 6.02 a litre.

Oil companies revise rates of petrol and diesel daily based on the average price of benchmark fuel in the international market in the preceding 15 days, and foreign exchange rates.