Japan's coast guard in East China Sea
Japan Coast Guard vessel PS206 Houou sails in front of Uotsuri island, one of the disputed islands, called Senkaku by Japan and Diaoyu by China, in the East China SeaReuters file photo

Japan has placed 12 of its coast guard vessels around the disputed chain of islands in the East China Sea. The deployment comes days after it inaugurated a new defence radar system in the region, and is meant to patrol the islands called Senkaku by Japan and termed Diaoyu by China.

The fleet comprises 1,500-tonne patrol ships – all of them newly inducted – and two Shikishima class helicopter carriers. All the newly-built ships, capable of high-speed manoeuvres, are fitted with 20mm guns and water cannons. Tokyo said the enhanced patrolling is to protect the waters surrounding the region, according to the Kyodo news agency.

Japan's Regional Coast Guard already has six 1,000-tonnne patrol ships and a helicopter-equipped vessel in the region. The latest addition to the fleet is bound to annoy China, which is locked in territorial disputes with multiple nations including Taiwan.

The latest deployment is expected to ease pressure on the Okinawa-based Coast Guard's 11th regional headquarters, which has been seeking help from other units to deal with tense maritime incidents in the region.

In recent months, there have been increased sightings of Chinese vessels near the hotly-contested archipelago. The forces of Japan and China have engaged in serious maritime encounters in the past.

Tokyo's military build-up in the region is part of a wider policy framed by Prime Minister Shinzo Abe to check Beijing's growing influence. Thanks to constant pressure from Washington, Japan is also set to deploy up to 10,000 military personnel over the next five years.

The Senkaku/Diaoyu archipelago came to the forefront of a territorial row after Tokyo said it was buying the uninhabited islands from private owners in 2012.