Okaz/Saudi Gazette NAJRAN — Fraudulent gasoline sales have been reported in Riyadh, Jeddah and other parts of the Kingdom, especially during the rainy season, said an official at the Ministry of Commerce and Industry. "Anti-trade fraud squads conduct campaigns in association with other government agencies including mayoralties to find out such malpractices," he said. The ministry's squads continuously monitor petrol stations to punish those who violate rules and regulations, he said. A petrol station is closed temporarily if we observe any violations. "We take gasoline samples from the station and send them to labs of Saudi Standards, Quality and Metrology Organization. After getting the result we take remaining measures," he said. Mandatory installing of devices at gas stations to show the color of gasoline will not be enough to prevent trade fraud in the sector, the official said, adding that some workers add some material to gasoline to look original. "We can find out mixing of low quality and high quality petrol by putting some material on a wooden stick and immersing it into the petrol tank. Any change in color of the material means mixing," the official said, adding that mixing could occur unintentionally during the rainy season. The ministry has received an explanation from the Agency for Petroleum and Mineral Resources that the gasoline color changes in accordance with crude, refining method and the colors added. According to the agency, a small change in color cannot be taken as an evidence for low quality as gasoline undergoes testing to cope with approved technical standards. Red and green colors are added to distinguish between various types of gasoline before loading. Social media activists have recently circulated a video clip in which a foreign worker is seen supplying green gasoline with an octane rating of 90 from the pump that supplies gasoline with an octane rating of 95. Citizens called for stiff punishment against violators. Ahmed Al-Aulaqi, a petrol station supervisor, told Okaz/Saudi Gazette that most stations lack the device used to distinguish between the various types of gasoline. Authorities have found mixing of gasoline 90 with 95 as it will appear with a different color at the time of supply.