North Korea on Wednesday repeated its denial of responsibility for the 2010 torpedo attack on the South Korean corvette Cheonan, arguing that the incident should not remain an “obstacle” to inter-Korean relations.

The denial came as South Korea marked the fourth anniversary of the attack that killed 46 sailors. Seoul has called for an apology for the provocation since an international investigation concluded in May 2010 that the 1,200-ton patrol ship was torpedoed by a North Korean midget submarine.

“It is an unprecedented, large-scale fabrication forged by those inclined toward extreme confrontation among ethnic (Koreans),” said a document from the inspection team of the powerful National Defense Commission, which was carried by the North’s Korean Central News Agency.

“The Cheonan incident should not be left as an artificial impediment to the improvement of the North-South relations, and to the reduction of tensions.”

The North also called for the lifting of Seoul’s so-called May 24 measures forbidding governmental economic exchanges and cooperation. The measures were put in place after the sinking of the Cheonan.

“Should (Seoul) want national reconciliation and unity, and improvement in the bilateral relations, it should broad-mindedly scrap all confrontational measures including the May 24 measures implemented in connection with the Cheonan incident,” the document said.

Clearing all hurdles to economic cooperation with Seoul is crucial for Pyongyang, which has been struggling to secure outside assistance to shore up its debilitated economy and feed its starving people.

Along with the calls for removing Seoul’s economic sanctions, the communist state has also sought to restart the multilateral aid-for-denuclearization talks, even when it has not shown any willingness toward denuclearization.

Pyongyang has adopted a policy of simultaneously pursuing nuclear armament and economic development. It apparently believes nuclear arms are a critical guarantor of the regime’s survival.

The document also urged Seoul to allow its NDC inspection group to get to the bottom of the sinking of the corvette. Immediately after Seoul’s Defense Ministry announced the result of an international investigation, Pyongyang demanded that its own investigators be dispatched to look into the case.

“If the South Korean authorities would like to continue to spread the ‘rumors’ about the North’s responsibility for the attack, it should accept our NDC inspection team’s investigation of the case,” said the document.

At Daejeon National Cemetery, some 5,000 people including bereaved families, citizens, soldiers and government officials gathered for a commemorative ceremony to remember the 46 deceased sailors and the warrant officer who died during the rescue and search mission.

The ceremony was hosted by the Ministry of Patriots and Veterans Affairs. Among the participants were Prime Minister Chung Hong-won and MPVA Minister Park Seung-chun.

“The freedom and peace we enjoy today is the crucial legacy that the sailors of the Cheonan have safeguarded by dedicating their lives for the nation. I pay deep respects to their noble sacrifices for the country,” President Park Geun-hye said in a statement read out by Minister Park.

By Song Sang-ho (sshluck@heraldcorp.com)