A homemade bomb thrown from a car caused minor damage and no injuries at the foundation of former Brazilian President Luiz Inacio Lula da Silva, authorities said on Friday.
The Lula Institute, located in downtown Sao Paulo, said no one was hurt in the Thursday night explosion that damaged a garage entrance. It called the blast a "political attack" against the leftist leader, who has not ruled out seeking the presidency again.
Once adored for leading the country during an economic boom and lifting millions of Brazilians from poverty, Lula has seen his reputation tarnished by a massive corruption scandal that has implicated his Workers' Party and its allies in power.
Lula himself is under investigation for allegedly using his influence to favor contracts for Brazil's largest engineering firm Odebrecht. Its chief executive officer, Marcelo Odebrecht, is in jail on charges of paying bribes on overpriced contracts with state oil company Petrobras.
Lula has denied any wrongdoing.
Following Odebrecht's indictment, news magazine Veja put Lula on its cover this week under the headline "His turn."
The approval rating of current Workers' Party President Dilma Rousseff, who won two terms on the coattails of Lula's enormous popularity, has sunk to just 7.7 percent in a recent poll. It showed Lula would lose if he ran for president again.