The attack by a group of men in Beijing came as nationalist sentiment deepens in both China and Japan over ownership of islands in the South China Sea.
Beijing apologized for the embarrassing incident on Monday, in which an unidentified man ripped the Japanese flag from the ambassador’s car amid rising tensions over disputed islands in the East China Sea.
A Chinese Foreign Ministry spokesman said the government was undertaking a “serious investigation” and would guarantee foreign diplomats’ safety. That did not stop Japanese Foreign Minister Koichiro Gemba from formally demanding an investigation on Tuesday, calling the incident “deplorable.”
Thousands of anti-Japanese protesters took to the streets of cities across China last weekend for the second straight week, burning Japanese flags and vandalizing Japanese restaurants and businesses.
The violence is the latest flare-up of a long-simmering row between Beijing and Tokyo over ownership of a handful of uninhabited rocky islands known here as the Diaoyu and in Japan as the Senkaku islands. The islands are surrounded by fishing grounds, and sovereignty would confer rights over nearby undersea oil and gas deposits.
The most recent war of words broke out between the two Asian neighbors a month ago, when Japanese Prime Minister Yoshihiko Noda appeared to suggest that his government might seek to buy the islands from their private Japanese owner, an idea championed by maverick Tokyo governor Shintaro Ishihara.
That prompted a sharp response from Chinese Foreign Ministry spokesman Hong Lei, who expressed Beijing’s “strong displeasure” with what he called Mr. Noda’s “highly irresponsible” remarks.
Tensions rose further when a group of Chinese activists from Hong Kong landed on one of the disputed islands on Aug.15, the 67th anniversary of Japan’s surrender at the end of World War II.
After they had been arrested by the Japanese coast guard and expelled from Japan, a group of right wing Japanese activists landed on another of the islands to make their own point for a couple of hours, before coast guard officials persuaded them to leave.
Nationalist and anti-Japanese sentiment is strong in China, where the authorities have long encouraged it in their citizens from an early age through history books that often inflame resentment against the former invaders.
The Chinese government faces a delicate task, however, not wanting to appear soft on Japan yet anxious to keep protests from turning into expressions of dissatisfaction with the Chinese authorities themselves, or from spilling over into violence that might seriously harm relations with Tokyo.
The Japanese authorities too appear anxious not to let the dispute get out of hand. The government yesterday refused a request from the Tokyo municipality for permission to land a delegation on the islands.