Four arrested in connection with deadly Brazil nightclub fire "They will not lack a penny, a document, an action," governor vows of investigators They are detained as part of an investigation into blaze that killed 231 "I think we will get to the bottom of this investigation," police chief says (CNN) -- Police arrested four people Monday in connection with a nightclub fire that killed 231 people in southern Brazil, CNN affiliate Band News reported. Two are club owners and the other two members of the band that was performing, it said. The detainees will be held initially for five days while authorities investigate Sunday's blaze in the Kiss nightclub in Santa Maria, according to Marcos Viana, a police official who spoke with state-run Agencia Brasil. The police chief in the province of Rio Grande do Sul said the investigation is to be divided into three parts: "The first line of inquiry has to do with the documentation: if the property was fit for operation and who the owners are. Are they real, formal owners? We will review all the documentation. The second stage of this investigation is expert analysis, which we will apply. And thirdly, important in itself, is the witness testimony. So, starting today, we will focus our efforts to the maximum in order to hear those people who were at the property at the time that it caught fire, at the business establishment. I think we'll get to the bottom of this investigation and, if possible, will identify those responsible by the time we complete this police investigation. The governor of Rio Grande do Sul promised that investigators would have all the resources they need to find out who is responsible. "From the executive office, they will not lack a penny, a document, an action or any other support, so that we can have an inquiry with depth and with the responsibility that it deserves," Tarso Genro said. Sunday during a band's pyrotechnic show. Guitarist Rodrigo Lemos Martins of the Gurizada Fandangueira band told the newspaper Folha de São Paulo that the fire ignited one song after the band had used fireworks in the show. But he said it was not clear what may have caused the fire. "There were many wires on the ceiling, and there could have been a short circuit," he said. Michele Pereira told Folha de São Paulo that her friend, 23-year-old Leandra Toniolo, was in the bathroom when the fire began. "I was on the opposite side, near the stage," Pereira said. "I would have had to go all the way across the arena -- against the mayhem -- to find her, and in the tumult it was impossible," she said. It was terrible, a scene from a horror film. ... There were fallen bodies throughout on the ground, many people who had fainted, many crying and trying to breathe with all that smoke. By the time Toniolo's mother found her daughter's body, it had been placed with others in a truck, Pereira said. How to protect yourself in a crowd In Santa Maria, mourners lined up in a series of funeral processions, and coffins were lined up in a gymnasium that authorities had turned into a morgue. By noon, 40 of 110 funerals planned for the day had been held at the city's municipal cemetery, its chief of staff told Band News. CNN's Tom Watkins, Helena Cavendish deMoura, Shasta Darlington and Chelsea J. Carter contributed to this report.