BRASILIA, Jan 6 (Reuters) - President Jair Bolsonaro criticized Brazil"s health regulator Anvisa on Thursday for authorizing the vaccination of children aged 5 to 11 years against COVID-19, one day after his health minister unveiled plans to inoculate that age group. Vaccine skeptic Bolsonaro said in a radio interview that he had not heard of children dying of COVID-19 and repeated that his daughter Laura, 11, would not be vaccinated. Bolsonaro said vaccines could have side effects on children, but gave no evidence. Anvisa and health regulators around the world have found that COVID-19 vaccines are safe from age 5 and up. "Are you going to vaccinate your child when the possibility of dying is almost zero? What is behind this? What are the interests of vaccine maniacs?" Bolsonaro stated. The Ministry of Health announced on Wednesday that it had bought 20 million pediatric vaccines developed by Pfizer Inc (PFE.N) and voluntary vaccination of children 5 to 11 years old will begin by the end of the month. read more In a social media broadcast later on Thursday, Bolsonaro stressed that the vaccination was not obligatory. "No town mayor or state governor can prevent a child from going to school for not being vaccinated," he said. Bolsonaro warned that Pfizer has not assumed responsibility for any side effects the vaccine could have in children, and said parents should immediately seek a doctor if their child developed chest pains or shortage of breath. Anvisa approved the Pfizer vaccine for children on Dec. 16, drawing heated criticism from people opposed to vaccines and the president, who suggested that children only be vaccinated with a doctor"s prescription. The ministry dropped the idea as impractical. Requiring a written prescription would discourage vaccination at a time when the more transmissible coronavirus variant Omicron is starting to spread in Brazil, health experts said at a public hearing. According to the national council of state health secretaries at least 300 children aged 5 to 11 had died in Brazil from COVID-19 by the start of December. Brazil"s Army differed from the president this week on how to deal with COVID-19. It ordered soldiers to get vaccinated, wear masks and maintain social distance, and warned them against spreading false news about the pandemic.