China's navy is stepping up its patrol around the disputed Diaoyo or Senkaku islands which lie between the mainland and Japan.
The Chinese navy entered the region on Tuesday night to conduct open-sea defence and offence training.
The patrols come as Taiwan, which also claims the islands, held live firing drills on the island of Penghu, off its western coast.
Al Jazeera's Stephanie Scawen reports.
Source: Al Jazeera