The Japanese Coast Guard will beef up border patrols following the intrusion of two Chinese ships into Japanese waters, NHK reported. Two Chinese vessels were spotted near the Japan-controlled Senkaku Islands in the East China Sea on Wednesday. The islands are also claimed by China. A collision between a Chinese trawler and Japanese patrol vessels in the same area last September heightened bilateral tensions. The Coast Guard is also mulling amending the law covering the navigation of foreign ships so that Japanese officials are able to warn suspicious vessels and order them to leave Japanese territory. Under the current law, officials must carry out on-site inspections before issuing eviction orders, NHK said.