Police are investigating online threats against two presidential candidates.

According to the National Police Agency, as of noon Friday there had been nine such threats, of which eight targeted liberal Democratic Party candidate Lee Jae-myung.

One of the eight cases has been transferred to the prosecution, while the police are handling the other seven.

The ninth threat targeted minor Reform Party candidate Lee Jun-seok.

The police have reinforced their security posture in case of any attacks on the candidates ahead of the June 3 election.