Investigators, With Reinforcements, Try Again to Detain South Korean Leader

Criminal investigators armed with a court-issued warrant prepared a second, much-anticipated operation early Wednesday to detain President Yoon Suk Yeol for questioning in connection with insurrection charges that stem from his short-lived imposition of martial law last month.

Police buses began massing before dawn outside the hilltop presidential compound where Mr. Yoon has been holed up since he was impeached — and suspended from office — by the National Assembly on Dec. 14. He was the first South Korean leader to place his country under military rule since the country began democratizing in the late 1980s.

When the investigators first visited his residence to serve a detention warrant on Jan. 3, they were outnumbered by presidential security agents. They were met by barricades of cars, bodyguards and soldiers and had to beat an embarrassing retreat after a standoff that lasted five and a half hours.

On Wednesday morning, with Mr. Yoon’s attorneys, lawmakers from his party and personnel from the presidential security service standing outside the compound gates, it appeared that he and his supporters were gearing up to resist the renewed effort for his detention.

The investigators have regrouped since their initial failed attempt to detain Mr. Yoon, renewing their warrant and saying they would bring in more police officers the next time they visited his residence. Police officials said they planned to deploy 1,000 officers, including units specializing in targeting drug and organized crime gangs.

For their part, Mr. Yoon’s security guards have since fortified the compound by deploying more buses and razor wire to block gates and walls. Mr. Yoon has vowed to “fight to the end” to return to office and said he won’t surrender to a court warrant that he considered illegal.

The effort to take in Mr. Yoon is the first time in South Korean history that the authorities are trying to detain a sitting president. The unfolding events have gripped the country, with news and social media channels livestreaming coverage. There are fears of a violent clash if neither side backs down.

A day before, the Constitutional Court began a hearing on whether to unseat Mr. Yoon, who did not show up. His lawyers said he feared the investigators would nab him if he left his presidential compound.

During the last attempt to serve the warrant, the Presidential Security Service, a government agency assigned to protect the president and his family, outnumbered the Corruption Investigation Office For High-ranking Officials, or C.I.O., which sought to detain him with the help of police. It deployed 200 bodyguards and soldiers to block 100 C.I.O. agents and police officers.

It was unclear how much manpower the presidential security team could muster in the new attempt to detain Mr. Yoon.

A military unit guards the perimeter of the presidential compound. But after the first standoff, the Defense Ministry told the presidential security service that it could no longer use the soldiers to block the serving of the warrant, saying this was not part of the soldiers’ duty.