High-speed diesel (HSD), petrol and kerosene are estimated to increase by up to Rs6 per litre on Friday for the next fortnight owing to higher international prices. Informed sources said the ex-depot petrol price was estimated to go up by Rs2-3 per litre depending on the final calculation on Jan 31. Kerosene and diesel prices are estimated to rise by about Rs6 per litre. The estimates are ba