ISTANBUL

In a rare public admission of failure, North Korea on Friday said that it has opened an investigation into a failed warship launch earlier this week, according to the state media.

"No matter how good the state of the warship is, the fact that the accident is an unpardonable criminal act remains unchanged, and those responsible for it can never evade their responsibility for the crime," the Korean Central News Agency (KCNA) said.

It said that, unlike the initial announcement, the probe revealed that there were “no holes made at the warship's bottom, the hull starboard was scratched and a certain amount of seawater flowed into the stern section through the rescue channel."

The launch of a newly built 5,000-ton destroyer failed in the eastern port city of Chongjin, as its stern slid ahead of the bow, causing structural damage and preventing the vessel from fully leaving the shipway.

Images of the ship show it lying on its side, partly in sea, partly on land, largely covered in bright blue tarpaulins.

The news agency said that it was estimated that two or three days would be needed "to keep the balance of the warship by pumping up the seawater from the flooded chamber and making the bow leave the slipway and 10 odd days to restore the warship's side."

It also said the warship's exterior damage is "not serious."

The procedure for restraining and investigating "those who are clearly responsible for the accident," has been started, according to the KCNA.

On Thursday, North Korean leader Kim Jong Un also condemned the accident as a “criminal act” stemming from “absolute carelessness, irresponsibility and unscientific empiricism," after the launch flop.