North Korea is suspected of using a Chinese ship to try to illegally send missile parts to Syria, where the government of President Bashar al-Assad is accused of war crimes in its bid to crush a 20-month uprising. br br The allegations came after South Korea seized a ship that reportedly carried graphite cylinders that could be used to create rockets in May, according to reported leaks by UN diplomats.br br The reports have put pressure on China – cited in leaks from the UN as the main hub for North Korea’s illegal arms trade - to investigate the accusation.br br Al Jazeera's Harry Fawcett reports from Seoul, South Korea's capital.