"China urges the U.S. side to thoroughly investigate the case, punish the troublemaker and take any necessary measures to effectively ensure the safety of Chinese diplomatic and consular institutions, and to avoid any further case of this kind," said Foreign Ministry spokesperson Hua Chunying.

　　China will closely watch the case as the investigation continues, Hua said at a regular press briefing.

　　The front door of the Chinese consulate-general in San Francisco was severely damaged in last Wednesday's arson attack, but no casualties resulted.