'N Korea may have 21 nukes or more'

North Korea may have produced an additional six or more nuclear weapons over the past 18 months, possibly bringing its total arsenal to more than 21 bombs, a US think-tank has said. The report came after International Atomic Energy Agency (IAEA) Chief Yukiya Amano said last week that North Korea might have reactivated a plant at Yongbyon for reprocessing plutonium for use in nuclear weapons.