North Korea and China are jointly developing several North Korean ports on its northeastern coast, Yonhap News Agency reported on Monday, citing a source in Beijing. Under joint deals struck between North Korean and Chinese firms, the two countries are re-developing as many as five ports along the eastern coast line linking the Sonbong port near the northern border to the Wonsan port in the lower part, the report said. "The Rajin port in the joint special economic zone between the North and China is officially under co-development and the Chongjin port is also said to be under joint development," the source was quoted as saying. The source's remarks constitute the first confirmation by a Chinese official of the two countries' joint development over ports other than the Rajin and Chongjin ports. The Yanbian Daily, a Korean-language newspaper in China, previously reported the North Korea-China deal over the Chongjin port development, which calls for their joint use and management of two piers at the port for 30 years. China also signed a deal with the North in 2008 to secure rights to use one pier at the Rajin port before reportedly gaining rights to use three other piers there recently.