South Korean President Lee Myung-Bak on Tuesday apologized to the nation over a string of bribery scandals involving his former aides and his elder brother-cum-political mentor. "I bow my head and apologize for causing concern to the people with these incidents," Lee said in brief televised remarks. The incidents are seen as a setback for Lee's conservative ruling party before a presidential election in December. He himself is barred from serving a second five-year term due to constitutional limits. Lee's elder brother Lee Sang-Deuk was arrested and detained earlier this month pending a corruption trial. Prosecutors allege the 76-year-old former lawmaker took 600 million won ($525,000) from the chairmen of two troubled savings banks between 2007 and 2011 in return for helping them avoid audits and punishment. The scandal was the latest in a series of corruption cases involving people close to the president, whose term ends in February 2013.