China vowed to investigate the incident involving Chinese protesters and the diplomatic car of U.S. Ambassador to China Gary Locke on Tuesday, with international media reports indicating that the vehicle was swarmed and harassed by street demonstrators.
Mr Locke's car was slightly delayed from entering the U.S. Embassy in Beijing because of the commotion created by the protesters who were originally situated in front of the neighbouring Japanese Embassy.
About 50 protesters surrounded and blocked the way of the U.S. car, The Associated Press reported on Thursday, though nothing untoward happened.
In a news briefing, Mr Locke said on Wednesday that he was not in danger at all during the whole episode that he recalled lasted only a few minutes.
He lauded the Chinese security forces their time timely interference, driving away the protesters quickly.
What happened according to a statement by China's Foreign Ministry was regarded by police authorities as "an individual case."
Beijing, however, has ordered an investigation, which is now underway, on the matter, the same statement said.
In Washington, State Department spokeswoman Victoria Nuland told AP that details gathered by U.S. embassy officials in China led them to preliminary conclusion that Mr Locke's vehicle arrived at the place at a wrong time.
The car was rolling into the embassy gate at the same moment Chinese protesters were gathered in front of the nearby Japanese Embassy and their ranks swelled over near the U.S. location, the State Department said.
Mr Locke's car became "a target of opportunity for protesters," Ms Nuland said.
Security on U.S. embassies around the world have been tightened following the attacks last week on American diplomatic posts and interests in response to the film Innocence of Muslims, which the Islamic world viewed as an insult.
One assault in Libya killed the U.S. envoy and three others.
The protests, however, in China stemmed from the territorial dispute between Beijing and Tokyo, with the two countries locked in rising tensions over ownership of a group of islets at the East China Sea.
The area is claimed by China as Diaoyu Islands while Japan said it is Senkayu Islands. The territory is uninhabited but is believed to hold rich reserves of oil and natural.
Last week, Tokyo nationalised the islands, further infuriating Beijing and setting off protests in mainland China.
Earlier this week, U.S. Secretary of Defence Leon Panetta urged both governments to resolve their differences peacefully in the interest of the whole Asia-Pacific region.
Washington, Mr Panetta added, will remain neutral on the matter.
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