After petrol, diesel is now nearing the Rs  100 per litre mark in Rajasthan as oil firms raised fuel prices yet again on Monday.

Petrol price was hiked by 28 paise per litre and diesel by 27 paise, according to a price notification of state-owned fuel retailers.

The hike -- the 21st 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 95.31 a litre, while diesel is now priced at Rs 86.22 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 border with Pakistan has the costliest fuel in the country -- petrol is priced at Rs 106.39 a litre and diesel at Rs 99.24.

Retail prices have risen after an increase in international oil prices on investors' optimism that improving demand and a dwindling supply glut may mean the market can absorb any additional production from OPEC and its allies.

Brent crude, the global oil price benchmark, is nearing USD 72 per barrel for the first time in two years.

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 101.52 in the city and diesel comes for Rs 93.58.

The hike on Monday was the 21st 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 21 increases, petrol price has risen by Rs 4.96 per litre and diesel by Rs 5.56 a litre.