North Korea's government has arrested four officials. This happened after a navy ship launch failed recently. State media said that leader Kim Jong Un believes the failure was caused by serious carelessness.

North Korea doesn't often announce harsh punishments for officials who fail at weapon tests or military shows. The recent arrests of four officials show how serious Kim Jong-un is about making his military stronger and improving discipline in the country.

A 5,000-ton destroyer was damaged on Wednesday while being launched. Kim Jong Un was there when a support structure at the back of the ship broke off. Satellite photos show the ship lying on its side, covered in blue material, and partly underwater.

Kim was very angry about the incident because the warship, which is the country's second destroyer, is very important for his plans to modernize the navy. He quickly blamed military officers, scientists, and people who work at the shipyard, saying it was a "criminal act" caused by extreme carelessness and a lack of scientific methods.

North Korea's official news agency reported on Monday that Ri Hyong Son, a high-ranking official in the Workers' Party, was arrested. He admitted he was 'very responsible' for the failed rocket launch.

KCNA reported on Sunday that three officials from Chongjin Shipyard were arrested due to an incident. The arrested officials included the chief engineer, the head of the hull construction workshop, and the deputy manager for administrative affairs.

Hong Kil Ho, the shipyard manager, was also called in for questioning, as KCNA reported earlier.

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

When Kim first became leader, he became known for ordering many executions and removing important officials, including his powerful uncle. However, people say he did these things mainly to strengthen his control and remove any possible threats to his rule. Recently, there have been fewer reports of executions or removals in North Korea, as Kim has gained complete power, just like his father and grandfather.

Kim has reportedly given special benefits to scientists and engineers who work on developing weapons, as he has been trying hard to increase his nuclear and missile supplies. 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 failure, saying, according to state media, that "failure is a necessary step towards success."

Experts think 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 said that North Korea needs a stronger navy, nuclear missiles, and other modern weapons to handle what he calls 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 big celebration. This ship is North Korea's biggest and most modern warship. State media reported that it can carry different weapons, such as nuclear missiles. Kim Jong Un said that building it was an important step forward for making North Korea's navy more modern.

North Korea said the second destroyer wasn't badly damaged, explaining that the right side of its body was scratched and some water got into the back part.

North Korea said on Friday that it would need about 10 days to fix things, but many people from other countries thought they probably made the damage seem less serious.