Rising petrol and diesel prices continued to trouble motorists on Friday, with rates in major metropolitan cities increasing by 56 paise per litre and 63 paise a litre respectively.

Friday marked the thirteen straight day of the hike, taking the cumulative increase in rates to Rs 7.11 for petrol and Rs 7.67 per litre for diesel in less than two weeks.

State-owned oil companies increased the petrol prices to Rs 78.37 per litre from Rs 77.81, while diesel rates were increased to Rs 77.06 a litre from Rs 76.43, according to a price notification of state oil marketing companies.

Rates have been increased across the country and vary from state to state depending on the incidence of local sales tax or VAT.

In Mumbai, Chennai and Kolkata patrol prices was at Rs 85.21, Rs 81.82 and Rs 80.13 respectively.

Diesel in these major cities was being sold at Rs 75.53 in Mumbai, Rs 74.77 in Chennai and Rs 72.53 in Kolkata.

The freeze in rates was imposed in mid-March soon after the government hiked excise duty on petrol and diesel to shore up additional finances.

Oil PSUs Indian Oil Corp (IOC), Bharat Petroleum Corp Ltd (BPCL) and Hindustan Petroleum Corp Ltd (HPCL) instead of passing on the excise duty hikes to customers adjusted them against the fall in the retail rates that was warranted because of fall in international oil prices to two decade low.

International oil prices have since rebounded and oil firms are now adjusting retail rates in line with them.