WINTERSET, Iowa (Reuters) - U.S. presidential candidate Hillary Clinton said on Saturday she did not send or receive classified information on a private email account while she was secretary of state.

"I did not send nor receive anything that was classified at the time," Clinton told reporters at a campaign event.

Clinton, the front-runner for the 2016 Democratic presidential nomination, has been criticized for using a private email account during her years as America's top diplomat.