TOKYO (AFP) - Three Chinese government ships entered the territorial waters of disputed Tokyo-controlled islands on Tuesday, Japan's coastguard said.

The three surveillance ships were navigating in the 12-nautical-mile zone around the Senkakus, which Beijing claims and calls the Diaoyus, as of 9.20 am local time (8.20am Singapore time), the coastguard said.

Chinese government ships have frequently spent time around the disputed island chain since Tokyo nationalised three of the isles last September.

However, the frequency of what Japan sees as intrusions on its sovereignty has decreased in recent months and the rhetoric between Asia's two largest economies has cooled.

The islands are also claimed by Taiwan.