North Korean officials have arrested four people because a recent navy ship launch failed. State media reported that leader Kim Jong Un said the failure happened due to their serious carelessness.

North Korea doesn't usually punish officials publicly and harshly if their weapons tests or military shows don't go well. This weekend's arrests of four officials demonstrate how serious Kim is about strengthening his military and improving discipline in the country.

A 5,000-ton destroyer was damaged on Wednesday during its launch ceremony in Chongjin, while Kim Jong-un was there. A part at the back of the ship broke off too early. Satellite photos showed the ship lying on its side, covered in blue, with some parts underwater.

Kim was very angry about the incident because the warship, which is the country's second known destroyer, is very important for his plan to make the navy more modern. He quickly blamed military officials, scientists, and shipyard workers, saying their actions were a "criminal act" caused by extreme carelessness and not using a scientific method.

On Monday, the official Korean Central News Agency announced that Ri Hyong Son, a high-ranking official in the Workers' Party, was arrested. He was held responsible for the recent failed launch.

KCNA reported on Sunday that three officials from Chongjin Shipyard were arrested because of the incident. They were the chief engineer, the head of the hull construction department, and the deputy manager for administration.

Hong Kil Ho, who manages the shipyard, was also asked to come in for questioning, as KCNA reported earlier.

On Thursday, North Korea's Central Military Commission told investigators that those responsible "cannot avoid being blamed for the crime." However, it is not clear what punishment the arrested officials will get.

When Kim first became leader, he was known for executing and removing many important officials, including his powerful uncle. However, experts say he did this mainly to gain stronger control and remove threats to his leadership. Recently, there have been fewer reports of executions or removals in North Korea, as Kim now has complete power, similar to his father and grandfather.

Kim has reportedly given special treatment to scientists and engineers who work on developing weapons, as he has been trying hard to increase his nuclear and missile weapons. He has given them new apartments in Pyongyang. Also, after a military spy satellite launch failed last year, he sent a supportive message to his scientists about the problem, saying that "failure is always a necessary step before success," according to state media.

Experts believe Kim wants to make good progress on his five-year plan to develop weapons, which he announced at a party meeting in early 2021. Kim has also said that North Korea needs a stronger navy, nuclear missiles, and other advanced weapons. He thinks these are needed to deal with the increasing security threats from the U.S. and its allies.

Last month, North Korea launched its first destroyer, a large 5,000-ton ship, with a lot of celebration. This ship is North Korea’s biggest and most modern warship, and state media reported it can carry various weapons, including nuclear missiles. Kim Jong-un called its construction "a breakthrough" in modernizing North Korea’s naval forces.

North Korea claimed the second ship only had minor damage, stating the right side had scratches and a small amount of water entered the back.

North Korea stated on Friday that they would need around 10 days to fix things, but many international observers thought the country probably didn't fully report the damage.