N Korea hacked Seoul's war plan

North Korean computer hackers have stolen hundreds of classified military documents from South Korea including detailed wartime operational plans involving its US ally, a report said yesterday.

The report came as South Korea said it was maintaining full military readiness following intense speculation of a possible ballistic missile test by the North as it marks a key anniversary.

North Korea often uses provocative tests to mark key historical commemorations and the country is celebrating the 72nd anniversary of the founding of the ruling Workers' Party on Tuesday.

Rhee Cheol-Hee, a lawmaker for the ruling Democratic party, said the hackers had broken into the South's military network last September and gained access to 235 gigabytes of sensitive data, the Chosun Ilbo daily reported.

Among the leaked documents was Operational Plans 5015 for use in case of war with the North and including procedures for "decapitation" attacks on leader Kim Jong-Un, the paper quoted Rhee as saying.

Rhee, a member of parliament's defence committee, could not be reached for comment but his office said he had been quoted correctly.

It also comes amid heightened fears of conflict on the Korean peninsula, fuelled by US President Donald Trump's continued threats of military action against Pyongyang to tame its weapons ambitions.

In his latest tweet over the weekend, Trump reiterated that diplomatic efforts with North Korea have consistently failed, adding that "only one thing will work".

Citing Seoul's defence ministry, Rhee said that 80 percent of the leaked documents had yet to be identified.

But the contingency plan for the South's special forces was stolen, he said, as well as details about annual joint military drills with the US and information on key military facilities and power plants.

A ministry spokesman declined to confirm the report, citing intelligence matters.

Pyongyang has a 6,800-strong unit of trained cyber-warfare specialists, according to the South Korean government. It has been accused of launching high-profile cyber-attacks including the 2014 hacking of Sony Pictures.

The European Union yesterday extended sanctions aimed at punishing North Korea for its nuclear and ballistic missile programmes, banning the import of textiles from the pariah state and limiting sales of crude oil.

                Earlier, the UN also slapped a global port ban on four vessels found violating sanctions against North Korea.

A spokesman for the South's Joint Chiefs of Staff said its military was closely monitoring the movements of the North Korean army and maintaining full readiness.

Consistent movements of personnel and equipment were being detected in certain locations in the North, Yonhap news agency reported, suggesting that preparations for another weapons test might be under way.

Pyongyang conducted its fifth nuclear test on the anniversary of the founding day of North Korea last year.

It remains unclear whether North Korea is holding official celebrations for the party anniversary or if its leader Kim Jong-Un is making any public appearances for the occasion.

The North's official media touted the party's byungjin policy -- which pushes for simultaneous development of nuclear weapons and the economy -- and added that military power was "the guarantee for victory".

"We must complete the construction of the national nuclear force by thoroughly upholding the party's byungjin policy," said a front-page editorial carried by the Rodong Sinmun newspaper to mark the party anniversary.

"We must hold high the banner of the great byungjin policy to accelerate the final victory in the anti-America Armageddon," it said.