North Korea has detained three individuals in connection with an accident during the launch of a new warship last week, state media reported Sunday.

The incident occurred Wednesday during a ceremony in the eastern port city of Chongjin for the launch of a newly built 5,000-ton naval destroyer. Pyongyang said "a serious accident occurred" when parts of the vessel's bottom were crushed.

North Korean leader Kim Jong Un described the mishap as a “criminal act caused by absolute carelessness.”

The Korean Central News Agency identified the detainees as Kang Jong Chol, chief engineer at the Chongjin shipyard; Han Kyong Hak, head of the hull construction workshop; and Kim Yong Hak, deputy manager for administrative affairs. According to KCNA, the three were “responsible for the accident.”

On Friday, KCNA reported that law enforcement had summoned shipyard manager Hong Kil Ho for questioning.

South Korea’s military said intelligence assessments by Seoul and Washington indicated that North Korea’s attempt to side-launch the ship had failed, resulting in the vessel listing in the water.

KCNA later reported that an "underwater and internal inspection of the warship confirmed that, unlike the initial announcement, there were no holes made at the warship's bottom," adding that the damage was "not serious."

Based on the ship's size and features, South Korea’s military believes it is similar to the 5,000-ton destroyer-class vessel Choe Hyon, which North Korea unveiled last month.

Pyongyang has said the Choe Hyon is equipped with the “most powerful weapons” and will “enter into operation early next year.”

Seoul's military has suggested the vessel may have been developed with Russian assistance, possibly in exchange for North Korea deploying troops to support Moscow in the war in Ukraine.

Analysts believe the warship involved in the recent accident may also have been constructed with Russian help.