BEIJING, Sept 14 (Xinhua) -- Two Chinese surveillance ship fleets have arrived at waters around Diaoyu Islands and its affiliated islets Friday morning and started patrol and law enforcement there.

It is the first time for Chinese surveillance ships to patrol there after the Chinese government announced on Monday the base points and baselines of the territorial waters of the Diaoyu Islands and their affiliated islets, as well as the names and coordinates of 17 base points.

These law enforcement and patrol activities are aimed to demonstrate China's jurisdiction over the Diaoyu Islands and its affiliated islets and ensure the country's maritime interests, according to a government statement.