Brazil's left-wing leader Luiz Inacio Lula da Silva urged his followers to continue "the fight" on Sunday evening at his first major rally since his release from prison a week ago."The fight isn't over," the former president chanted to several tens of thousands of cheering supporters in the north-eastern city of Recife."After seeing so many people mobilise across the country, I want to say: 'The fight is not over.' The fight cannot end because we still want more," Lula said, referring to the thousands of left-wing activists who mobilised across Brazil during his 580-day incarceration."The 'Free Lula' campaign must become something even bigger!" he added, as the crowd welcomed him with cries of, "Lula, warrior for the Brazilian people!"READ | Brazil's Lula jailed to keep him from 2018 election: reportLula, who held presidential office from 2003 to 2010, was arrested in April 2018 for corruption, though he said he was innocent. He was sentenced to eight years and 10 months in prison.The 74-year-old was released on November 8 in a politically sensitive Supreme Court ruling that could free thousands of convicts.On Sunday, he returned to Recife, the capital of his home state Pernambuco, to take part in a music festival organized in his honour.READ | Brazil ex-leader Lula returns to jail after grandson's funeralThough he claimed multiple times he didn't want to discuss politics during a music festival, Lula viciously attacked his political rival, right-wing President Jair Bolsonaro, during his speech."You can be sure that every minute of the rest of my life will be devoted to freeing our country from this gang of militiamen who have seized it," he said, referring to the Bolsonaro family's suspected links with paramilitary groups.Lula has already given three public speeches since his release from prison, but the one in Recife was the first time he had spoken to such a large crowd.