Yoon supporters gathered in the pre-dawn hours near the presidential residence on Friday, with the numbers swelling into the hundreds as they vowed to block any attempt to arrest Yoon, with some chanting "President Yoon Suk-yeol will be protected by the people".
Officials from the Corruption Investigation Office for High-ranking Officials (CIO), which is leading a joint team of investigators into Yoon's brief declaration of martial law on December 3, arrived at the gates of the presidential compound shortly after 7am and entered on foot.
Police and prosecutors arrived at the gates of President Yoon Suk-yeol's compound on Friday morning. (AP PHOTO)
Once inside the compound, the CIO and accompanying police faced cordons of Presidential Security Service (PSS) personnel, as well as military troops seconded to presidential security, media reported.
South Korea's defence ministry said the troops were under the control of the PSS.
The CIO called off the effort to arrest Yoon about 1.30pm due to concerns over the safety of its personnel due to obstruction, and said it "deeply regretted" Yoon's attitude of non-compliance.
"It was judged that it was virtually impossible to execute the arrest warrant due to the ongoing stand-off," the CIO said in a statement.
Yoon's lawyer said in an earlier statement on Friday that execution of an invalid arrest warrant against Yoon is unlawful, and that they would take legal action, without elaborating.
The arrest warrant, approved by a court on Tuesday after Yoon ignored multiple summons to appear for questioning, is viable until January 6, and gives investigators only 48 hours to hold Yoon after he is arrested.
President Yoon Suk-yeol sent shock waves through South Korea when he declared martial law. (AP PHOTO)
Investigators must then decide whether to request a detention warrant or release him.
The CIO said on Friday it would review the situation and decide on possible next steps.
Yoon sent shock waves through the country with a late-night announcement on December 3 that he was imposing martial law to overcome political deadlock and root out "anti-state forces".
Within hours, however, 190 MPs had defied the cordons of troops and police to vote against Yoon's order.
About six hours after his initial decree, Yoon rescinded it.
He later issued a defiant defence of his decision, saying domestic political opponents are sympathetic to North Korea and citing uncorroborated claims of election tampering.
Some supporters chanted "President Yoon Suk-yeol will be protected by the people" as they rallied. (AP PHOTO)
Two South Korean military officials, including army chief Park An-su who was named martial law commander during the short-lived declaration last month have been indicted after being detained by prosecutors who are investigating insurrection charges, Yonhap reported on Friday.
Kim Yong-hyun, who resigned as Yoon's defence minister after playing a major role in the martial law decree, has been detained and was indicted last week on charges of insurrection and abuse of power.
Insurrection is one of the few criminal charges from which a South Korean president does not have immunity.
Yoon's lawyers have said the arrest warrant was illegal and invalid because the CIO did not have the authority under South Korean law to request a warrant.
Yoon has been isolated since he was impeached and suspended from power on December 14.
Separate from the criminal investigation, his impeachment case is before the Constitutional Court to decide whether to reinstate or permanently remove him.
A second hearing in that case is scheduled for later on Friday.
