North Korea has arrested a fourth official over the failed launch of a new warship that has enraged the country's leader, Kim Jong Un.
Ri Hyong-son, deputy director of the ruling Workers' Party's Munitions Industry Department, was "largely responsible for the serious accident" last week, state-run news agency KCNA said on Monday.
The 5,000-ton destroyer had tipped over and damaged its hull, in what Kim had described as a "criminal act" that "severely damaged the [country's] dignity and pride".
The vessel is being repaired under the guidance of an expert group, KCNA said.
