(CNN) -- The United States warned Saturday that China's military claim to airspace over a disputed island chain creates the risk of "misunderstanding and miscalculation." The creation of an "Air Defense Identification Zone" by China, which its top defense official described as an early-warning system, comes amid rising tensions between China and Japan over claims to the islands that are believed to have large oil reserves. "This unilateral action constitutes an attempt to change the status quo in the East China Sea. Escalatory action will only increase tensions in the region and create risks of an incident," U.S. Secretary of State John Kerry said.China releases a map and coordinates that identify its "Air Defense Identification Zone"The zone includes disputed islands -- known as Senkaku by Japan and Diaoyu by ChinaChina began air patrols over the zone on SaturdayDefense Secretary Chuck Hagel called the move is an attempt to destabilize the status quo in the region
_ was outraged, as were protesters who marched through several Chinese cities calling for boycotts of Japanese products and urging the government to give the islands back.