PYONGYANG, Oct. 22 (Xinhua) -- A senior official of the Democratic People's Republic of Korea (DPRK) on Thursday warned the Republic of Korea (ROK) not to interfere in the DPRK's fortification project along the southern border, the official Korean Central News Agency (KCNA) reported. Kim Yo Jong, department director of the Central Committee of the Workers' Party of Korea, made the remarks in response to a latest