SEOUL — North Korea has arrested four people it claims bear responsibility for a launch accident last week that left leader Kim Jong Un’s newest warship lying on its side and partially submerged in a shipyard, state-run media has reported.

The four people detained included Ri Hyong Son, vice department director of the Munitions Industry Department of the Party Central Committee, “who was greatly responsible for the occurrence of the serious accident,” a report from the Korean Central News Agency (KCNA) on Monday said.

On Sunday, KCNA said three others had been detained: Kang Jong Chol, chief engineer of the Chongjin Shipyard where the accident occurred, Han Kyong Hak, head of the hull construction workshop, and Kim Yong Hak, deputy manager for administrative affairs.

Kim last week called the botched launch, which he witnessed, “a criminal act” and vowed to punish those responsible.

Last Wednesday’s accident resulted from a malfunction in the launch mechanism that caused the stern of the as-yet unnamed 5,000-ton destroyer to slide prematurely into the water, crushing parts of the hull and leaving the bow stranded on the shipway, KCNA reported on Thursday in a rare admission of fault from an otherwise highly secretive state.

State media reported on Friday that the damage to the warship was less than North Korea’s initial estimate, saying there were no holes in the hull, although it was scratched along the starboard side. It also said “a certain amount of seawater flowed into the stern section.”

Repairs could take about 10 days, the report said. Though analysts are skeptical.

Kim had ordered the destroyer to be restored before the late June plenary session of the ruling Workers’ Party, calling the matter one of national honor.

Satellite imagery shows most of the warship covered in blue tarps at the launch site, making it difficult for experts to determine the full extent of the damage it suffered.

But analyst Carl Schuster, a former US Navy captain, said repair work could take up to six months, well beyond Kim’s June target.

“If the hull damage extends across the ship’s port side covered by the tarp, then we are looking at four to six months of repair work,” he said.

Repairs could be complicated depending on the amount of sea water that entered the warship, according to Schuster.

The interior of the ship would need to be thoroughly flushed with fresh water and then dried to prevent “salt crust” from forming on metal surfaces, he said.

“If it gets into joints and things, then it becomes destructive,” Schuster said.

But the flushing work cannot begin until the ship is righted and any holes in the hull are patched, he said.

KCNA reported Monday that “the work for completely restoring the balance of the warship is being actively conducted,” but it did not give a timeline.

Satellite images from Maxar Technologies taken Sunday and supplied to CNN showed the ship still on its side, still mostly covered in blue tarps as smaller boats swarmed around it.

South Korean lawmaker and defense analyst Yu Yong-weon said last week that rushing the launch of the ship likely led to the problems encountered on Wednesday and warned hasty repairs could cause more problems down the line.

Schuster echoed that thinking, saying optics may be more important than military value to the Kim regime.

“If Kim Jong Un says, ‘I want that ship fitted out in six months,’ they’ll take shortcuts to make it happen. And usually when you do that you wind up with a ship that’s not, shall we say optimal for operations? But it meets the propaganda criteria.” — CNN