The prosecution has indicted President Yoon Suk Yeol on charges of insurrection in connection with Yoon's martial law imposition on December 3.

The prosecution's special investigation team probing the martial law case indicted Yoon on Sunday, 54 days after he declared martial law.

With the indictment, Yoon has become the first sitting president in South Korea's history to be indicted under detention.

The prosecution said that it has decided it is appropriate to indict Yoon after reviewing the evidence collected in the probe team's investigation into Yoon's accomplices, as well as other evidence secured by the police in their own probe.

Yoon is accused of conspiring with former Defense Minister Kim Yong-hyun and others to declare an unconstitutional and illegal martial law and to incite an insurrection with the purpose of violating the Constitution.

The suspended president is also alleged to have dispatched martial law troops to the National Assembly.

The indictment comes just one day before Yoon's pretrial detention period was set to end, following a court rejection of the prosecution's request to extend Yoon's detention on Saturday.