At least 30 bodies have been found after warehouse fire occurred in Oakland, United States on Friday night, media reports said.The worst fire in the history of Oakland, took place during an electronic music party in a two-story warehouse converted into a party venue and probably a residence in an industrial neighbourhood, Xinhua news agency reported.While officials said there was no sign of fire alarms and no evidence of a sprinkler system in the structure, authorities have said the loft building did not have permits and investigators have not found the course of the fire.Sergeant Ray Kelly of Alameda County Sheriff's Office in California said about 20 per cent of the warehouse, which was burnt out by a fire starting about 11.30 p.m. (local time) on Friday, had been searched.At the first briefing on Sunday, officials increased the death toll from 9 to 24. Heavy machinery was brought in to the site on Saturday to help with cleaning up the debris and shore up the structure.In a previous press conference, Kelly said he did not know how many people were in the building, and how many left, meaning that there was no exact number of people unaccounted for. On Sunday, he said the number could rise, as well as the death toll.The building is now a crime scene investigated by local and federal law enforcement agencies. Oakland mayor Libby Schaaf pledged a full investigation into the incident.