South Korea's impeached President Yoon Suk-yeol has attended a court hearing to fight a request by investigators to extend his detention on accusations of insurrection.
Yoon on Wednesday became the country's first sitting president to be arrested, in a criminal probe related to his short-lived declaration of martial law on December 3.
Investigators requested a detention warrant on Friday to extend their custody of Yoon for up to 20 days.
He has been refusing to talk to investigators and has been held in Seoul Detention Centre since his arrest.
Thousands of protesters have rallied to support impeached South Korean President Yoon Suk-yeol. (AP PHOTO)
After the hearing, Yoon returned to Seoul Detention Centre to await the court's decision, expected on Saturday or Sunday.
The hearing at Seoul Western District Court lasted almost five hours.
Yoon spoke for about 40 minutes during the hearing, Yonhap said, citing Yoon's lawyer.
"(Yoon) sincerely explained and answered questions on factual relationships, evidence and legal principles ... We will quietly wait for the court to decide," Yoon's lawyer Yoon Kab-keun said after the hearing.
Yoon had decided to attend the hearing "to restore his honour by directly explaining the legitimacy of emergency martial law and that insurrection is not established", his lawyer said earlier on Saturday.
TV channels showed a convoy of about a dozen cars and police motorbikes escorting Yoon from the detention centre to the court, and later back to the detention centre.
Since police broke up a crowd of Yoon's supporters blocking the gate of Seoul Western District Court in the morning, thousands of supporters gathered after the hearing began at about 2pm (0500 GMT) Saturday in front of a police bus barricade at the court chanting "release the president".
"There are so many supporters of President Yoon Suk-yeol around the court, who still believe in the rule of law and are defending the president," said Lee Se-ban, 30.
Yoon's lawyer said that after the hearing he was expected to return to Seoul Detention Centre to await the court's decision, due on Saturday or Sunday.
Multiple people were arrested by police for trying to break into the court grounds, including a young man who tried to escape, according to a Reuters witness.
Insurrection, the crime alleged against Yoon by the Corruption Investigation Office for High-ranking Officials, is one of the few from which an incumbent South Korean president does not have immunity.