A major accident occurred at the launch ceremony for a new North Korean naval destroyer, state media reported Thursday, with leader Kim Jong Un calling the mishap a "criminal act".

At a ceremony to launch a new 5,000-ton vessel in the eastern port city of Chongjin on Wednesday "a serious accident occurred", the official Korean Central News Agency (KCNA) said.

South Korea's military said North Korea also fired "multiple unidentified cruise missiles" on Thursday, which were detected near the North's South Hamgyong province after being "fired toward the East Sea", also known as the Sea of Japan.

Blaming "inexperienced command and operational carelessness" for the destroyer's botched launch -- which was observed by Kim -- KCNA said there was a mishap which left "some sections of the warship's bottom crushed".

It said the accident managed to "destroy the balance of the warship".

Kim watched the entire incident and declared it a "criminal act caused by absolute carelessness", warning it "could not be tolerated".

He said the "irresponsible errors" of officials responsible would be "dealt with........

© International Business Times