President Yoon Suk Yeol testified on Tuesday that he ordered troops to be sent to the offices of the National Election Commission(NEC) while the country was under martial law, saying the discovery of “nonsense ballots” during his time as a prosecutor led him to conclude there were problems with elections.

Yoon made the statement during the fifth hearing of his impeachment trial at the Constitutional Court.

The suspended president said he ordered then-defense minister Kim Yong-hyun to dispatch troops to the NEC’s offices, adding that their mandate was not to conduct any criminal investigations, but to check the NEC’s computer systems and how they were operating.

Yoon said he gave Kim the order while discussing plans for martial law on November 29 or 30.

He also said that before declaring martial law, he did not tell his Cabinet ministers that the purpose of his decree was to send a “warning.”