Chinese dredging vessels are purportedly seen in the waters around Mischief Reef in the disputed Spratly Islands in the South China Sea in this still image from video taken by a P-8A Poseidon surveillance aircraft provided by the United States Navy May 21, 2015. REUTERS/U.S. Navy/Handout via Reuters

WASHINGTON (Reuters) - Commercial satellite imagery appears to show that China has deployed a surface-to-air missile system in the South China Sea, U.S. State Department spokesman Mark Toner said on Wednesday.

“Commercial imagery appears to indicate that China has deployed a surface to air missile system on a disputed outpost in the South China Sea. If this is true, we believe this will raise tensions further in the region,” Toner told reporters.