SEOUL—South Korea’s legislature voted to impeach acting President Han Duck-soo on Friday after he declined to make judicial appointments needed to advance the impeachment of his predecessor, extending the political upheaval that began with a short-lived martial law declaration earlier this month.

Han’s impeachment occurs amid weeks of political chaos following Yoon’s brief declaration of martial law on December 3, which lasted only six hours but led to widespread protests. This move intensified the political vacuum that has gripped South Korea.

South Korea's acting president faces an impeachment vote as the Constitutional Court meets for its first hearing on Friday in the case of President Yoon Suk Yeol, who was impeached and suspended from duties after a short-lived martial law.