South Korea's presidential guards and military troops have prevented authorities arresting impeached President Yoon Suk-yeol in a tense six-hour stand-off inside Yoon's compound in the heart of Seoul.
Yoon is under criminal investigation for insurrection over his December 3 martial law bid that stunned South Korea and lead to the first arrest warrant to be issued for a sitting president.
"It was judged that it was virtually impossible to execute the arrest warrant due to the ongoing stand-off," the Corruption Investigation Office for High-ranking Officials (CIO) said in a statement on Friday.
The CIO officials and police evaded hundreds of Yoon supporters who gathered in the pre-dawn hours near his residence on Friday, vowing to block the arrest "with our lives".
Some chanted "President Yoon Suk-yeol will be protected by the people", and called for the head of the CIO to be arrested.
Officials from the CIO, which is leading a joint team of investigators into possible insurrection charges related to Yoon's brief declaration of martial law, arrived at the gates of the presidential compound shortly after 7am and entered on foot.
Once inside the compound, the CIO and police were outnumbered by cordons of Presidential Security Service (PSS) personnel, as well as military troops seconded to presidential security, a CIO official told reporters.
More than 200 PSS agents and soldiers formed several layers of human chains to block the CIO and police, the official said.
While there were altercations and PSS agents appeared to be carrying firearms, no weapons were drawn in the stand-off, the official said.
Yoon, who has been isolated since he was impeached and suspended from power on December 14, was not seen during the stand-off, he said.
South Korea's defence ministry said the troops were under the control of the PSS.
The CIO is considering its next steps are calling off the effort to arrest Yoon about 1.30pm due to concerns over the safety of its personnel, saying it "deeply regretted" Yoon's attitude of non-compliance.
The police, who are part of the joint investigation team, have designated the PSS chief and the deputy as suspects in a criminal case for obstruction of official duty and issued summons for them to appear for questioning on Saturday, Yonhap news reported.
Yoon's arrest warrant, approved by a court on Tuesday after he ignored multiple summons to appear for questioning, is viable until January 6.
After the arrest effort was suspended, Yoon's legal team said the CIO had no authority to investigate insurrection and it was regrettable that it had tried to "forcibly execute an illegal and invalid arrest and search warrant" in a sensitive security area.
The interim head of Yoon's People Power Party welcomed the suspension and said the investigation must be carried out without detaining Yoon.
The warrant gives investigators only 48 hours to hold Yoon after he is arrested, then investigators must decide whether to request a detention warrant or release him.
Yoon sent shock waves through Asia's fourth-largest economy and one of the region's most vibrant democracies with his late-night announcement 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, and about six hours after his initial decree, Yoon rescinded it.
He later issued a defiant defence of his decision, saying domestic political opponents were sympathetic to North Korea and citing uncorroborated claims of election tampering.
Two South Korean military officials, including army chief Park An-su who was named martial law commander during the short-lived declaration, have been indicted after being detained by prosecutors 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.
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 was held on Friday and the court set the first oral arguments for January 14.
