North Korea makes arrests over botched ship launch

North Korea has detained three shipyard officials over an accident during the launch of a new warship on Wednesday, state media has reported.

Parts of the 5,000-ton destroyer's bottom were crushed during the launch ceremony, tipping the vessel off balance.

An investigation into the incident, which North Korea's leader Kim Jong Un described as a "criminal act", is ongoing.

KCNA, North Korea's official news agency, identified those detained as the chief engineer of the northern Chongjin shipyard where the destroyer was built, as well as the construction head and an administrative manager.

The report said that the three were "responsible for the accident".

On Friday, KCNA said the manager of the shipyard, Hong Kil Ho, had been summoned by law enforcers.

Satellite images showed the vessel lying on its side covered by large blue tarpaulins, and a portion of the vessel appeared to be on land.

North Korea's state media did not mention any casualties or injuries at the time, downplaying the damage.

KCNA reported that there were no holes on the ship's bottom - contrary to initial reports.

"The hull starboard was scratched and a certain amount of seawater flowed into the stern section," the agency said.

Kim said on Thursday the accident was caused by "absolute carelessness, irresponsibility and unscientific empiricism".

He added that those who made "irresponsible errors" would be dealt with at a plenary meeting next month.

It is not clear what punishment they might face, but the authoritarian state has a woeful human rights record.

It is uncommon for North Korea to publicly disclose local accidents - though it has done this a handful of times in the past.

This particular accident comes weeks after North Korea unveiled a similar 5,000-ton destroyer, the Choe Hyon.

Kim had called that warship a "breakthrough" in modernising North Korea's navy and said it would be deployed early next year.