At least two persons were charred to death and more than three others sustained burn injuries in a fire that broke out at an oil tanker on the Karnafuli river at Chattogram port on Thursday, officials said. The deceased have been identified as the oil tanker's crew members -- Nizam Uddin, 40 and Ruhul Amin, 45. The three injured crew members -- Abu Sufian, Sahabuddin and Monir -- have been admitted to Chittagong Medical College and Hospital.   According to local sources, the fire broke out at the engine room of inland oil tanker MT Iravati at the Super Petro Chemical Jetty of the port around 7am.   A number of firefighting units from the Bangladesh Fire Service and the Navy were soon pressed into service and it took them a good four hours to contain the blaze, officials said,   Newton Das, deputy assistant director of Chattogram Fire Service and Civil Defence told UNB that an electrical short-circuit at the engine room of the vessel might have triggered the devastating fire.   Also read: Gas cylinder blast in Sylhet: Injured woman dies at DMCH   Shilbot Barua, an assistant sub-inspector of police posted at Chittagong Medical College and Hospital, said that the condition of two of the injured -- Monir and Shahabuddin -- is critical. Also read: 2 killed, 10 injured in Bhola gas cylinder blast   A probe has been ordered into the fire accident, officials said.