Chinese warships patrol disputed waters in the South China Sea.
Four surveillance vessels deployed since last week practice maritime inspections in waters also claimed by the Philipines and other countries.
The government says they are enforcing ''law and order within China's territorial waters".
(SOUNDBITE) (Mandarin) CHINESE FOREIGN MINISTRY SPOKESPERSON LIU WEIMIN SAYING:
"I want to point out that China hopes that peace and stability is maintained in the Asia Pacific area, and also hopes that relevant sides will do more for peace and stability in the region."
Tensions between the two countries have increased since the Philippines revealed it may ask for help from U.S. spy planes to monitor its waters.
Taiwan, Brunei, Vietnam and Malaysia also lay claim to parts of the resource-rich South China Sea.
Lindsey Parietti, Reuters
