Bathinda, April 29 (ANI): Prime Minister Manmohan Singh has given clear indication that petroleum product prices are going to be hiked, but the common man would be protected from its effects. While inaugurating the Guru Gobind Singh Refinery, owned by a joint venture between HPCL and Mittal Energy of Singapore, HMEL, at Bathinda in Punjab, he said that domestic sources of crude oil and gas are inadequate to meet the growing demands of our rapidly expanding economy.