China on Wednesday pledged to strictly follow the United Nations resolutions and the country's own non-proliferation export controls in response to previous reports of Pyongyang violating UN sanctions by exporting suspected missile parts onboard a Chinese-registered ship to Syria in May.

Foreign Ministry spokesman Hong Lei said China opposes proliferation and the delivery of weapons of mass destruction.

"We will deal with activities which violate UN Security Council resolutions and Chinese laws and regulations," he told a regular news conference.

Republic of Korea authorities seized a shipment of 445 graphite cylinders — disguised as lead pipes — that can be used in missiles in a Chinese-registered vessel called Xin Yan Tai at the ROK port of Busan, Reuters quoted diplomats from UN Security Council as saying.

Analysts said the export, if confirmed, means Pyongyang may receive further sanctions as it violated UN bans on trading materials related to nuclear and missile technology. The Northeast Asian country has been sanctioned because of its nuclear tests in 2006 and 2009.

But the case, which involved many parties amid the 20-month Syrian crisis and instability on the Korean Peninsula, needs to be scrutinized before more sanctions are issued, they added.

The shipment to Syria was arranged by a trading company in the Democratic People's Republic of Korea, and the Syrian company Electric Parts, which was to receive the cylinders, may be a subsidiary of the DPRK firm, according to Reuters.

On Oct 24 Seoul briefed the UN Security Council's DPRK sanctions committee about the seizure, and China offered to help investigate the circumstances surrounding the incident, the report said.

"It's possible that the crew of the Chinese ship had no idea what this shipment really was. It's good that China has expressed a willingness to investigate," Reuters quoted an UN diplomat as saying.

The ship, registered in Shanghai, was built in 2005 and is owned by a Shanghai shipping company, China Classification Society, Kyodo News Agency reported.

China, a key coordinator in the DPRK nuclear issue, will absolutely work with related parties to thoroughly investigate the case as a responsible permanent member of the Security Council, said Wang Junsheng, a researcher of East Asian studies with the Chinese Academy of Social Sciences.

But the investigation is not an easy task, said Zhang Liangui, an expert on Korean studies at the Party School of the Central Committee of the Communist Party of China. "The UN sanctions imposed have prohibited Pyongyang from exporting weapons of mass destruction, but they have no specific regulations on exports of regular weapons. The so-called missile parts fall in the gray zone since they can be used for military and civilian purposes," Zhang said.

The severe shortage of foreign exchanges from chronic sanctions has propelled Pyongyang to develop and export military technologies, he added. The export in May came after Pyongyang's failed launch of a satellite in April, which the West believed was a missile test. The Security Council adopted a presidential statement calling for tougher sanctions against the country shortly after the attempt.

Contact the writers at zhaoshengnan@chinadaily.com.cn and liuyedan@chinadaily.com.cn