Sao Paulo authorities Thursday announced plans for more safety checks at night spots following last Sunday\'s deadly fire in southern Brazil. Under a deal between state and municipal authorities, inspection teams are to sweep discos and bars looking to prevent accidents like the fire that killed 235 people in a nightclub in Santa Maria, an official statement said. Sao Paulo Governor Geraldo Alckmin praised the agreement, saying it was aimed at cutting red tape to make people safer. \"Joint surveillance is more effective -- it brings better results when it comes to protecting people\'s lives,\" he said. \"We do not want to disrupt the work of business people. It is more surveillance and less bureaucracy,\" the governor added. On Tuesday, authorities in Brazil\'s most populous state -- around 1,000 kilometers (600 miles) north of the city where the fire broke out -- had already launched a state-wide operation, dubbed \"Maximum Prevention,\" under which firefighters were to inspect night entertainment spots. According to the fire department, 5,200 night spots across Sao Paulo state state and more than 200 in its main city, home to 11 million people, were to be inspected. Meanwhile, four people remain under detention for their presumed responsibility in the tragic Santa Maria fire that left at least 235 people dead and more than 100 hospitalized. Investigators are under pressure to solve the case as Brazil, host of the 2014 World Cup and the 2016 summer Olympic Games in Rio de Janeiro, tries to prove it can safely host large public events. Police on Monday arrested the two owners of Santa Maria\'s Kiss nightclub, as well as two musicians who allegedly took part in the ill-fated pyrotechnic show. Santa Maria police chief Marcelo Arigony told reporters Tuesday that the musicians bought a flare for the show \"that they knew was designed exclusively for outside use,\" but which was much cheaper than indoor flares. Arigony also ran down a long list of nightclub security violations, including a lack of emergency lights, fire extinguishers that did not work and may have been only for show, and an overcrowded dance floor.