State-owned oil companies on Thursday have increased the prices of petrol by Rs 1.82 per litre from midnight. Earlier, the petroleum ministry said it is up to the oil companies to decide on raising the rates of the deregulated commodity. After today's increase, petrol in Delhi will cost Rs 68.64 a litre. The rates will vary in other cities according to local levies. This is the second hike in petrol prices in less than two months and it came on a day when the food inflation rose "dangerously" to 12.21 per cent for the week ended October 22. "It is for them (oil companies) to decide. They will take a decision at a right time," Oil secretary G C Chaturvedi told reporters. Slamming the hike, BJP leader Sushma Swaraj wrote on micro-blogging site Twitter, "Petrol price hiked again - another blow to the common man from an insensitive government." Indian Oil, HPCL and Bharat Petroleum had last hiked petrol prices by Rs 3.14 a litre on September 16, when the rupee was valued at about Rs 48 per US dollar. The exchange rate is now over Rs 49 per dollar. State-owned oil firms Indian Oil, Hindustan Petroleum and Bharat Petroleum had earlier hiked petrol prices by Rs 3.14 a litre on September 16 when the rupee was ruling at about 48 to a US dollar. The local currency has depreciated further. The rupee on Thursday closed at 49.14/15 against the US dollar. The government had in June last year deregulated or freed petrol from all price controls but the retail rates have not moved in line with cost as high inflation rate forced the oil companies to seek 'advice' from parent oil ministry before revising rates.