Seoul (AP): South Korean police questioned the chief of the presidential security service on Friday as the two agencies clashed over attempts to detain impeached President Yoon Suk Yeol.

The Corruption Investigation Office for High-Ranking Officials and police are planning a second attempt to bring Yoon into custody as they jointly investigate whether his brief martial law declaration on Dec 3 amounted to an attempted rebellion. The presidential security service blocked an earlier attempt to detain Yoon at his official residence, which he has not left for weeks.

Park Jong-joon, the presidential security chief, says that his duty is to protect the president and warned of “bloodshed,” as critics said that his agency is becoming Yoon's private army.

Park ignored two summonses before appearing for questioning on Friday over allegations of obstructing justice, a week after his forces repelled dozens of anti-corruption and police investigators from Yoon's official residence.

The anti-corruption office and police have vowed to make a second, more forceful effort to detain Yoon, warning that members of the presidential security staff could be arrested if they get in the way.

The embattled president remains holed up at his official residence in Seoul, where the presidential security service has fortified the grounds with barbed wire and rows of vehicles blocking the roads.

Yoon made a short-lived declaration of martial law and deployed troops to surround the National Assembly on Dec. 3, which lasted only hours before lawmakers managed to get through the blockade and voted to lift the measure.

His presidential powers were suspended when the opposition-dominated Assembly voted to impeach him on Dec. 14 and accused him of rebellion. His fate now rests with the Constitutional Court, which has begun deliberating on whether to formally remove Yoon from office or reject the charges and reinstate him.

There's also speculation that police may attempt to detain Park and other leaders of the presidential security service before trying again to execute the detainment warrant against Yoon, which was renewed by a Seoul court on Tuesday.

Speaking to reporters upon arriving for police questioning, Park again criticized the efforts to detain Yoon, saying that the investigation should proceed in a manner “appropriate for the status of an incumbent president” and the “dignity of the nation.”

“Many citizens are surely deeply concerned about the possible conflict and confrontation between government agencies,” Park said. “I came here today with the belief that under no circumstances should there be any physical clashes or bloodshed, and am hoping to prevent such incidents from occurring.”

Park said he made several calls to the country's acting leader, Deputy Prime Minister Choi Sang-mok, urging him to mediate an alternative approach with law enforcement and also made similar requests to Yoon's lawyers, but did not receive a satisfactory response.

Yoon's lawyers accused the police of trying to undermine the leadership of the presidential security service.

“This is an abnormal move that displays a disregard for national security,” the lawyers said in a texted statement.

While the presidential security act mandates protection for Yoon, it does not authorize the service to block court-ordered detainments and some legal experts say the presidential security service's action last week may have been illegal.

Asked in parliament about the presidential security service's effort to block the detention, National Court Administration head Cheon Dae-yeop said Friday that “resistance without a legitimate reason can constitute a crime, such as obstruction of official duties.”

Although the president himself has wide-ranging immunity from prosecution while in office, that does not extend to allegations of rebellion or treason.

Yoon's lawyers have questioned the legitimacy of a new detention warrant against Yoon issued by the Seoul Western District Court, arguing that the anti-corruption agency lacks legal authority to investigate rebellion charges or order police to detain suspects.

They also argue that detention and search warrants against Yoon cannot be enforced at his residence, citing a law that protects locations potentially linked to military secrets from search without the consent of the person in charge - which would be Yoon.

Yoon's lawyers have urged the agency to either indict the president or seek a formal arrest warrant, a process that requires a court hearing. However, they have said that Yoon would only comply with an arrest warrant issued by the Seoul Central District Court, which handles most key requests in high-profile cases.

They accuse the agency of deliberately choosing another court with an allegedly favourable judge, even though the official residence is located in the jurisdiction of the Western District Court.