TOKYO — More than 3,000 Japanese have staged an anti-China demonstration in Tokyo amid a diplomatic row between the two Asian powers.The protesters on Saturday demanded China give up its claim to a group of disputed islands in the East China Sea.The long-running dispute over the islands flared after a September collision between Japanese patrol vessels and a Chinese fishing boat. The Chinese boat captain was arrested but later released.The protest in the Japanese capital came a day after Japan launched a probe into the possible leak of a video showing the collision.The islands are called Diaoyu in China and Senkaku in Japan. They are controlled by Tokyo but also claimed by Beijing.