Special services are being held in Brazil in memory of the 237 people who died in a nightclub fire in the city of Santa Maria a week ago. More than 4,000 people attended a service in Santa Maria itself on Saturday night, and a silent vigil was held in front of the nightclub, Kiss. Santa Maria's mayor says he plans to turn the building into a memorial site. The death toll rose to 237 on Sunday after a 22-year-old man died of injuries sustained in the fire. More than 100 people remain in hospital. Medical kits have been flown in from the US to treat survivors who were exposed to the dangerous fumes. Two owners of the nightclub and two band members have been arrested. Safety concerns Special services were held in cities across Brazil's southern-most state, Rio Grande do Sul, where Santa Maria is located. In Santa Maria itself, people dressed in white and placed flowers and posters in memory of those who had lost their lives. A service in their honour was also held at the foot of the Christ the Redeemer statue in Rio de Janeiro, the AFP news agency reports. The fire is believed to have broken out after the band playing in the nightclub last Sunday set off cheap fireworks meant for outdoor use. The flames spread quickly over the ceiling which was covered with foam for soundproofing, the BBC's Julia Carneiro reports from Rio de Janeiro. The venue had only one exit and is believed to have been filled way over capacity, so panic ensued as people failed to find a way out, she adds. Investigators say many lives could have been saved if regulations had been properly observed. A safety inspection of nightclubs, restaurants and bars across Brazil has led to more than 150 temporary closures in the past week. Brazil's Congress is set to revise legislation in an attempt to strengthen safety regulations and allay concerns ahead of the 2014 World Cup and 2016 Olympics.