Seoul (Reuters) - Investigators found bird feathers and blood in the two engines of the Boeing jet that crashed in South Korea on Dec. 29, a person familiar with the probe told Reuters on Friday.

Trump defense secretary nominee Pete Hesgeth ruffled feathers in S. Korea with his written statement to the Senate panel overseeing his confirmation

Yoon Suk Yeol this week became South Korea’s first sitting president to be detained. The Seoul Detention Center is a far cry from his official residence.

South Korea's impeached President Yoon Suk Yeol was arrested on Wednesday as part of an investigation into alleged insurrection, and in between being questioned the suspended leader is expected to be held in a solitary cell at a detention centre.

South Korean police detained impeached President Yoon Suk Yeol at his residence in Seoul on Wednesday local time, ABC News confirmed.

President Yoon Suk Yeol, who has already been impeached, became South Korea’s first sitting leader to be detained after weeks of openly defying authorities.

President Yoon Suk Yeol was arrested and taken for questioning after more than 3,000 police officers marched on his residence in the early hours of Wednesday.

South Korea looks set for a dramatic political showdown this week as impeachment proceedings kick off against suspended President Yoon Suk Yeol, who remains holed up in his fortified residence evading arrest for a separate criminal investigation.

Recently suspended South Korean president Yoon Suk Yeol was arrested early Wednesday by the country's Corruption Investigation Office for High-ranking Officials, ending a political standoff triggered by Yoon's short-lived decision to impose martial law last month.

Yoon Suk Yeol became the first South Korean leader to be held by criminal investigators, ending a long standoff after he imposed martial law.

North Korea warned Friday that it would exercise its right to self-defense "more intensively" as it condemned recent joint air drills among South Korea, the United States and Japan.