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.

South Korea has voted to impeach its acting president Han Duck-soo, two weeks after parliament voted to impeach its President Yoon Suk Yeol. Some 192 lawmakers voted for his impeachment, more than the 151 votes needed for it to succeed.

As the president awaits an impeachment trial, the country’s interim leader may, too, be ousted. The currency has plunged as the crisis has deepened.