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 vote was the second major impeachment in two weeks after President Yoon’s ill-fated martial law bid set off turmoil. The country’s currency has plunged.

The impeachment of South Korea’s acting President Han Duck-soo has plunged the country into further political turmoil, coming less than two weeks after lawmakers impeached President Yoon Suk Yeol.

South Korea's acting President Choi Sang-mok vowed to continue trilateral cooperation with Japan and the United States, saying on Friday his country's diplomacy remains steadfast despite an unprecedented political crisis at home.

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.

South Korean lawmakers voted on Friday to impeach acting president Han Duck Soo, barely two weeks after Yoon Suk Yeol was removed from the presidency over his imposition of martial law. A total of 192 lawmakers in the opposition-controlled parliament voted to impeach Han - significantly more than the simple majority required.

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 Korean investigators on Saturday again asked the country’s acting president to clear the way for the arrest of impeached President Yoon Suk Yeol after a six-hour standoff earlier this week thwarted his detainment.

Protesters in South Korea are calling for President Yoon Suk Yeol to be arrested as a warrant expires at midnight on Monday. The chief of security for Yoon, Park Chong-jun, said Sunday he could not cooperate with the arrest efforts for the impeached leader,

South Korea's main opposition party vowed on Tuesday to impeach acting president Han Duck-soo but reversed an earlier plan and decided to wait until later in the week, party officials said, as the risk of further political uncertainty heightened.