SEOUL, South Korea — Two of President Park Geun-hye’s closest aides, including her culture minister, were arrested Saturday on charges that they were involved in drawing up a blacklist of thousands of artists and writers deemed unfriendly to Ms. Park and excluding them from government-controlled support programs.

Ms. Park’s powers have been suspended as she faces an impeachment trial on charges of corruption and abuse of power. The blacklisting of artists is another element of the case against Ms. Park in her impeachment trial at the Constitutional Court. The court will decide in the coming months whether to end her presidency on the charges filed by the National Assembly on Dec. 9.

On Saturday, a special prosecutor investigating Ms. Park’s case arrested Culture Minister Cho Yoon-sun and Kim Ki-choon, Ms. Park’s former presidential chief of staff, on charges of abusing official power in connection with the blackballing of the artists.

Ms. Cho is the first sitting member of Ms. Park’s cabinet to be arrested in the investigation.

Revelations about the blacklist have infuriated the public, prompting national introspection about South Korea’s young democracy and its authoritarian past. Huge crowds of people who have marched in central Seoul on recent weekends demanding Ms. Park’s impeachment have also called for the arrests of Ms. Cho and Mr. Kim.