The increase effected by the Union Government in the prices of petrol, diesel and cooking gas on Wednesday came as a shock for the residents of Chandigarh and Panchkula and many of them rushed to the nearby petrol pumps to fill the tanks of their vehicles at the old rates as the new prices would be effective from midnight. Several prominent petrol pumps, especially the CITCO service station in Sector IX, saw serpentine queues. However, some pumps put up "Not Available' signboards and when customers quarrelled with the staff, they were curtly told that the supplies had run out.