SEOUL -?Republic of Korea (ROK)?Foreign Minister Yun Byung-Se said Tuesday that the Democratic People's Republic of Korea (DPRK) is believed to operate its Yongbyon nuclear complex, located 90 km north of Pyongyang.

"Many still believe that (the nuclear reactor) continues to be in operation," Yun said during a parliamentary audit of the foreign ministry.

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His comments came after a US think tank claimed in the Oct 5 report that Pyongyang may have shut down its plutonium-producing reactor in Yongbyon citing the recent satellite imagery.

The Institute for Science and International Security (ISIS) said the imagery showed neither steam venting from the reactor nor the discharge of cooling water, which indicates the shutdown of the 5-megawatt reactor for refueling or maintenance purposes.

Yun said it needs not to have the same views as the report about whether the Yongbyon nuclear reactor has been shut down or the reason for the shutdown if it is true.

The DPRK had reportedly restarted its mothballed reactor in Yongbyon that can produce plutonium and expanded the size of uranium enrichment operation at the Yongbyon complex.