Japan's trade minister warned Friday that Tokyo would take «bold action» if it confirms that China is building a pipeline in disputed gas exploration sites in the East China Sea, according to AP. Trade Minister Shoichi Nakagawa said that Japan has detected a Chinese vessel carrying a massive load of pipes headed for the region, and Beijing has not responded to its requests for an explanation. «The number of pipes was obviously too many to just dig down. Then what are they for? I can assume the reason, but I'd rather not speak out,» Nakagawa said, hinting at a possible pipeline construction. «We must always watch very closely.» Nakagawa said he learned from «reliable sources» and also saw a video showing the ship heading for the Tianwaitian and Chunxiao fields «carrying huge heap of pipes» _ enough to build a pipeline to mainland China. Nakagawa said China is believed to be bringing undersea oil from the two gas fields to Shanghai through pipelines and natural gas to Ningbo in Zhejian province. The two countries have been feuding over claims to undersea gas deposits in the area and the delineation of their exclusive economic zones. The row is part of the broader troubled relations between the two sides.