The U.S. says it has expressed concern to the Chinese authorities . China says it is investigating what it describes as an `` isolated case '' About 50 protesters gathered around the car , some throwing objects . The United States has expressed concern to China about the unusual disturbance on Tuesday , which comes at a sensitive time for American diplomats following the death of Ambassador Christopher Stevens in an attack in Libya last week . A spokesman for China's Foreign Ministry said in a statement that Beijing was "seriously concerned" about reports of violence and urged all sides "to exercise restraint and avoid any actions which could lead to further escalation
The U.S. says it has expressed concern to the Chinese authorities . China says it is investigating what it describes as an `` isolated case '' About 50 protesters gathered around the car , some throwing objects . A spokesman for China's Foreign Ministry said in a statement that Beijing was "seriously concerned" about reports of violence and urged all sides "to exercise restraint and avoid any actions which could lead to further escalation