New Delhi: A fire broke out at the Hindustan Petroleum Corporation Limited (HPCL) Visakh refinery in Gajuwaka industrial area of Andhra Pradesh’s Visakhapatnam on Monday night, sending up a dense plume of black smoke that was visible across nearby neighbourhoods. Officials said the blaze started in the pitch tower of the recently commissioned Residue Upgradation Facility (RUF) in the refinery. A loud blast followed by large flames left residents of surrounding areas anxious for a while, The Hindu reported.Describing the scene, an HPCL employee said: “Flames quickly spread to nearby areas, sending thick clouds of black smoke into the sky and engulfing the surrounding locality.”Hindustan Times reported that scared residents in nearby areas rushed out of their homes.Malkapuram police inspector E. Narasimha Rao circulated a voice message to calm residents, saying the situation was under control. According to him, the refinery’s own fire and safety department’s fire tenders were rushed to the spot to put out the fire, so engines from outside were not needed. Further, he added that there were no fatalities or injuries reported so far. The RUF converts heavy vacuum residue oil into higher-value fuels such as diesel and petrol. The high temperatures at which the unit runs, combined with the thick petroleum pitch, produced the heavy smoke. Due to the fire incident, structural damage within the pitch unit is expected to be significant, as per TH report. As a precautionary measure, refinery officials have cut power to the affected section and shifted personnel to safer spots.HPCL officials told TH that a technical committee would investigate what exactly caused the fire. They said the main processing units were still running and that fuel supplies would not be disrupted.