SEOUL (Reuters) -South Korean investigators again asked the country's acting president on Saturday to order the presidential security service to comply with an arrest warrant for impeached President Yoon Suk Yeol.

The plane crash is the first major test for South Korea’s acting president, Choi Sang-mok, who was appointed the interim leader only on Friday, as the country grapples with a political crisis at the highest levels.

Acting President Han Duck Soo blocked the appointment of three judges that Parliament had selected to oversee his predecessor's impeachment.

The impeachment of Han Duck-soo, acting president since Yoon was impeached on Dec. 14 for declaring martial law, has thrown South Korea's once-vibrant democratic success story into uncharted territory.

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.

South Korea's opposition Democratic Party submitted an impeachment motion against embattled acting President Han Duck-soo on Thursday in the latest challenge to the country's leadership structure.

South Korea's acting president has been impeached less than a month after the impeachment of his predecessor, Yoon Suk Yeol, for imposing martial law. And, how'd the "Beyoncé Bowl" do on Netflix?

South Korea's anti-corruption agency said on Monday that it had asked police to take over the execution of an arrest warrant for impeached President Yoon Suk Yeol. The request comes after a failed attempt to execute an arrest warrant on Friday following a tense stand-off with presidential guards who formed a human chain to block access by the investigators.