North Korean leader Kim Jong Un and his top deputies have pushed for a crackdown on officials who abuse their power and commit other "unsound and non-revolutionary acts", state media reported on Monday.
Meanwhile, South Korea's military said North Korea test-fired what appeared to be artillery shells toward the sea on Sunday, one day after Mr Kim called for greater defence capability to cope with outside threats.
South Korea's Joint Chiefs of Staff said it detected several flight trajectories believed to be North Korean artillery on Sunday morning.
It said in the statement that South Korea maintained a firm military readiness in close coordination with the United States amid boosted surveillance on North Korea.
During a national security council meeting convened to discuss the launches, South Korean officials expressed concern that North Korea is upgrading weapons systems that pose a direct threat to South Korea and reaffirmed they would sternly deal with such North Korean efforts, according to South Korea's presidential office.
The North's artillery tests draw less outside attention than its missile launches but its forward-deployed long-range artillery guns are a serious security threat to South Korea's populous metropolitan region, which is only 50 kilometres from the border.
The suspected artillery launches were the latest in a spate of weapons tests by North Korea this year in what foreign experts call an attempt to pressure its rivals Washington and Seoul to relax international sanctions against Pyongyang and make other concessions.
In March, North Korea test-launched an intercontinental ballistic missile capable of reaching the mainland US in breach of a 2018 moratorium on big missile tests.
In a speech at a ruling party meeting last week, Mr Kim underscored the need to strengthen his country's military capability, saying the current security environment is "very serious".
Mr Kim's speech, carried by state media, didn't mention the United States or South Korea but he still set forth "militant tasks" to be pursued by his armed forces and scientists, a suggestion that he would press ahead with his high-profile arms build-up plans.
A possible new nuclear test by North Korea would be the seventh of its kind.
Some experts say North Korea will likely use the test to build warheads to be mounted on tactical nuclear weapons aimed at hitting targets in South Korea.
Kim pushes for internal unity
At home, Mr Kim is seeking greater internal unity to overcome a COVID-19 outbreak and economic difficulties.
It wasn't clear what specific acts were mentioned at the ruling Workers' Party meeting on Sunday.
However, possible state crackdowns on such alleged acts could be an attempt to solidify Mr Kim's control of his people and get them to rally behind his leadership in the face of the domestic hardships, some observers say.
Senior party secretaries discussed "waging a more intensive struggle against unsound and non-revolutionary acts including abuse of power and bureaucratism revealed among some party officials", the official Korean Central News Agency said.
Mr Kim ordered the authority of the party's auditing commission and other local discipline supervision systems to be bolstered to promote the party's "monolithic leadership" and "the broad political activities of the party through the strong discipline system", KCNA said.
Mr Kim has in the past two years occasionally called for struggles against "anti-socialist practices" at home amid outside worries about his country's fragile economy that has been battered by pandemic-related border shutdowns, UN sanctions and his own mismanagement.
The North's elevated restrictions on movement in the wake of the COVID-19 outbreak could cause a further strain on the country's economic difficulties, some experts say.
On May 12, North Korea admitted the Omicron variant of the coronavirus had infected people, and it has subsequently said about 4.5 million people — more than 17 per cent of its 26 million people — have fallen ill with fevers.
It said only 72 people had died.
Foreign experts widely doubt the outbreak was North Korea's first, and they believe the statistics being disclosed in state media are manipulated to prevent political damage to Mr Kim while bolstering internal control and promoting his leadership.
During a Workers' Party conference last week, Mr Kim claimed the pandemic situation has passed the stage of "serious crisis" and ordered officials to remedy "the shortcomings and evils in the anti-epidemic work" and take steps to build up the country's anti-pandemic capability.
AP/ABC
