Japanese authorities say they have deployed a new Coast Guard vessel to help patrol a disputed island chain in the East China Sea.

Officials say the 1,300-ton patrol boat arrived Tuesday at Ishigaki port in Okinawa, about 170 kilometers from the islands known in Japan as Senkaku and in China as Diaoyu. An incident near the islands sparked a diplomatic crisis between Japan and China last year.

The deployment of the ship, which can accommodate helicopter landings, means Japan now has three vessels on hand to respond to any incident in the islands. Officials say the number of Chinese vessels cruising near the Japanese-administered islands has more than doubled since last year's incident.

That incident was sparked when Japan arrested a Chinese fishing captain whose boat collided with a Japanese Coast Guard vessel.

China responded by cutting off all high-level contacts with Japan and suspending shipments to Japan of rare earth minerals, which are vital to many Japanese manufacturing industries.

Relations between the countries have returned to normal, but they remain wary over each other's maritime activities.