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 opposition-controlled National Assembly voted Friday to impeach acting President Han Duck-soo despite vehement protests by governing party lawmakers, further deepening the country’s political crisis set off by President Yoon Suk Yeol’s stunning imposition of martial law and ensuing impeachment.