North Korean authorities on Sunday detained three shipyard officials over the failed launch of a naval destroyer this week.
North Korea's state news agency, the Korean Central News Agency (KCNA), reported that the chief engineer, head of the hull construction workshop and deputy manager for administrative affairs at Chongjin Shipyard were detained by authorities.
The 5,000-ton-class ship, which is Pyongyang's second known destroyer, could be seen lying sideways with a blue cover on it in satellite images.
North Korea says no serious damage
The ship's stern was damaged during a launch ceremony in the northeastern port of Chongjin on Wednesday, which was attended by leader Kim Jong Un.
Kim wants to build a strong naval force to counter US influence in the region, and this was seen as an embarrassment to him.
He called it a "criminal act caused by absolute carelessness, irresponsibility and unscientific empiricism," blaming military officials, scientists and shipyard staff for the failure.
North Korea's first destroyer was launched last month. State media reports said it is capable of carrying different weapons, including nuclear missiles.
"There is no additional identified damage to the warship and the field rehabilitation promotion team is pushing ahead with the rehabilitation plan as scheduled," KCNA said.
Pyongyang denied that there had been any serious damage, saying the hull on the starboard side was scratched and some seawater flowed into the stern section.
On Friday, North Korea said it would take 10 days for repairs, but observers say it could take a lot longer.
