Three Chinese government ships entered the territorial waters of disputed Tokyo-controlled islands on Monday, Japan's coastguard said.

The three surveillance ships were navigating in the 12-nautical-mile territorial waters around the Senkakus, which Beijing claims and calls the Diaoyus, at around 1:30 pm (0430 GMT), the coastguard said.

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

The islands are also claimed by Taiwan.