Volkswacht Bodensee - A mug shot and a solitary cell for S. Korea's impeached president

Yoon was arrested in a dawn raid last week, becoming the first sitting South Korean head of state to be detained in a criminal probe on insurrection charges over his botched declaration of martial law.

South Korea was plunged into political chaos by Yoon's December 3 martial law declaration, which lasted just six hours before lawmakers voted it down. They later impeached him, stripping him of his duties.

Yoon also faces a concurrent Constitutional Court case deciding whether to uphold that impeachment, as well as the criminal investigation over which he was detained.

His lawyers said late on Monday he would attend a Constitutional Court hearing on Tuesday afternoon for the first time.

A court approved Yoon's formal arrest warrant Sunday, citing concerns he would destroy evidence, and he went from being a temporary detainee to a criminal suspect facing an indictment and trial.

Yoon was given a 12-square-meter (129-square-feet) cell at the Seoul Detention Center in Uiwang on Sunday, according to Shin Yong-hae, commissioner general of the Korea Correctional Service.

He was "assigned to one of the standard rooms used by regular inmates", Shin told lawmakers during a parliamentary session.

Yoon's cell -- which typically would hold five or six people, Yonhap news agency reported -- is similar in size to those where past presidents have been detained, Shin said.

The suspended leader, whose powers have been transferred to an acting president but who remains sitting head of state, also had his mug shot taken and underwent physical examination like his fellow inmates.

"The individual cooperated well with the procedures without any particular issues," Shin said.

According to prison regulations, Yoon will have to change from his normal clothes into a khaki prison uniform, and he will also have been assigned an inmate number.

Prison officials have said his cell includes a small table to use for eating and studying, a small shelf, a sink and a toilet. It also includes a television, but viewing time is strictly restricted.

Inmates are allowed to go out for an hour every day for exercise, and shower once a week, but local media have reported that authorities will attempt to prevent him coming into contact with other inmates.

His personal security detail will accompany him whenever he leaves his cell, reports say.

- Court attack -

Yoon has claimed the criminal probe is illegal and resisted arrest for weeks, vowing to "fight to the end". His die-hard supporters attacked the court building on Sunday after his detention was extended.

Dozens of people, including YouTube streamers, have been arrested over a riot at the Seoul court, police said on Monday, and 51 police officers were injured in the attack, including some with head injuries and fractures.

Up to 35,000 of his supporters were outside the court on Saturday, according to a police document seen by AFP.

About 300 people gathered near the rear entrance of the court and began "throwing objects such as glass bottles, rocks, and chairs into the court grounds", according to the police report.

"Some 100 protesters entered the court premises, smashing windows of the first floor, damaging the walls and entering inside the building," it said.

Yoon declined to attend questioning on Monday by the Corruption Investigation Office (CIO), the body in charge of the probe, the CIO said in a statement.

It then attempted to force him to attend but Yoon and his lawyers rebuffed their attempts, it said.

The CIO said it halted its attempt to force him to attend "in accordance with human rights protection regulations".

S.Gantenbein--VB