- Insurrection can be punishable by life imprisonment or death, although South Korea has not conducted an execution in decades.
- Yoon's lawyers had urged the prosecutors to immediately release him from what they call illegal custody.
[LI[ South Korean prosecutors have indicted the impeached President Yoon Suk Yeol on charges of leading an insurrection over his imposition of martial law.
Prosecutors in South Korea have indicted the impeached President Yoon Suk Yeol on charges of leading an insurrection with his short-lived imposition of martial law, the main opposition party said.
"The prosecution has decided to indict Yoon Suk Yeol, who is facing charges of being a ringleader of insurrection," Democratic Party spokesman Han Min-soo told a press conference.
"The punishment of the ringleader of insurrection now begins finally."
Yonhap news agency reported that the Seoul Central District Prosecutors' Office indicted Yoon over rebellion in connection with his 3 December decree that plunged the country into massive political turmoil.
There was no immediate comment from the prosecutors' office.
Yoon's lawyers had urged the prosecutors to immediately release him from what they call illegal custody.
Read more: The full text of South Korea's martial law decree
Under criminal investigation, Yoon has been in custody since 15 January after becoming the first sitting president to be arrested.
Insurrection is one of the few criminal charges from which a South Korean president does not have immunity.
It is punishable by life imprisonment or death, although South Korea has not executed anyone in decades.
Yoon and his lawyers argued at a Constitutional Court hearing last week that he never intended to fully impose martial law but had only meant the measures as a warning to break political deadlock.
In parallel with his criminal process, the top court will determine whether to remove Yoon from office or reinstate his presidential powers.
They have 180 days to decide.
South Korea's opposition-led parliament impeached Yoon on 14 December, making him the second conservative president to be impeached in the country.
Yoon rescinded his martial law after about six hours after lawmakers from the main opposition party, confronting soldiers in parliament, voted down the decree.
Soldiers equipped with rifles, body armour and night-vision equipment, were seen entering the parliament building through smashed windows during the dramatic confrontation.
This story was originally published by ABC News.