South Korean presidential guards prevent arrest of impeached Yoon after tense stand-off

South Korea's presidential guards and military troops prevented authorities from arresting impeached President Yoon Suk Yeol on Friday 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 Dec. 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 standoff," the Corruption Investigation Office for High-ranking Officials (CIO) said in a statement.

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 7 a.m. (2200 GMT Thursday) 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.

As many as 200 formed a human chain to block the CIO and police, the official added.

South Korea's Ministry of National Defense said the troops were under the control of the PSS.

The CIO called off the effort to arrest Yoon around 1:30 p.m. due to concerns over the safety of its personnel due to obstruction, and said it "deeply regretted" Yoon's attitude of non-compliance.

Insurrection is one of the few criminal charges from which a South Korean president does not have immunity.

His arrest warrant, approved by a court on Tuesday after Yoon ignored multiple summons to appear for questioning, is viable until Jan. 6.

Yoon has been isolated since he was impeached and suspended from power on Dec. 14.

In a statement 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 statement warned police against supporting the arrest effort.

The interim head of Yoon's People Power Party welcomed the suspension and said the investigation must be carried out without detaining Yoon.

The current warrant gives investigators only 48 hours to hold Yoon after he is arrested. Investigators must then decide whether to request a detention warrant or release him.

Yoon sent shockwaves 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 lawmakers 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.

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 currently 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.