South Korea's former defence minister, Kim Yong-hyun, who claimed full responsibility for the president's failed attempt to place the country under martial law last week, has tried to take his own life, an official said.

Authorities found him while making the attempt in his detention centre on Tuesday night, Shin Yong-hae, the justice ministry's correctional agency chief, told lawmakers.

In the wake of Yoon's shock martial law order, Kim resigned last week along with other top presidential staff.

He had been detained on Sunday for investigation, before he was formally arrested on insurrection charges.

Kim was in stable condition following the attempt, Shin said.

Kim is among top officials who are facing investigations for their role in Yoon's short-lived martial law order, which has sparked widespread fury in South Korea.

Tens of thousands of people have taken to the streets calling for the president's resignation or impeachment.

Yoon is also being investigated for alleged insurrection. While he has apologised for the martial law declaration, he has not accepted growing calls for him to step down.

Kim, who was named defence minister in September, said he apologised "deeply" in a statement on Tuesday and said "all responsibility for this situation lies solely with me (BBC)