U.S. aircraft carrier strike group patrols in South China Sea

A U.S. aircraft carrier strikegroup has begun patrols in the South China Sea, the U.S. navysaid on Saturday, amid renewed tension over the disputedwaterway.

China's Foreign Ministry on Wednesday warned Washingtonagainst challenging its sovereignty, responding to reports the U.S. was planning fresh naval patrols in the SouthChina Sea.

The navy said the force, including Nimitz-class aircraftcarrier USS Carl Vinson, began routine operations in the SouthChina Sea on Saturday. The announcement was posted on theVinson's Facebook page.

China lays claim to almost all of the South China Sea, including several of its contested shoals, islands and reefs, and recently conducted war games in the region. The country has beenconstructing artificial islands with airstrips in the seafor a number of years.

The sea is rich in potential oil and gas reserves, and about $5 trillion USworth of trade passesthrough every year.