SHANGHAI (Reuters) - China's top graft buster followed up a series of inspections of elite sports training centers by reiterating its warning against corruption in the run-up to the Rio Olympics on Monday.

The Beijing Sport University and the Olympic Training center were among departments visited by inspectors attached to the sports ministry, the ruling Communist Party's Central Commission for Discipline Inspection (CCDI) said on its website on Monday.

While the units had made some improvements to their attitudes to moral codes and discipline, the CCDI said, inspectors found problems with their understanding of rules and a lack of timely efforts to address these issues.

It called for the units to encourage a frugal atmosphere for the approaching Dragon Boat Festival, keep a lookout for corruption risks and vulnerabilities, and improve supervision in order to create a positive environment for the Rio Olympics.

The inspections come after the CCDI rapped the sports ministry in May for not taking the country's campaign against corruption seriously enough.

China, which is aggressively seeking to stamp out graft in Communist Party and government ranks, has also sought to remove corruption from its sports establishment, particularly within soccer, which has been hit by several match-fixing scandals.

Chinese athletes bagged the most gold medals at the 2008 Beijing Olympics, a feat accompanied by a wave of nation pride, and came second to the United States four years later at the London Olympics.

The Rio Olympics take place from Aug. 5-21.

(Reporting by Brenda Goh, editing by Nick Mulvenney)