Defend
the Diaoyu Islands to the death, one banner said. Another said, “Even if China is covered with graves, we must kill
all Japanese.” Another photograph showed a handwritten sign taped to the entrance of Suning, a popular electronics store,
telling customers it was no longer selling Japanese products. Some protests appear to have turned violent. According
to several postings, demonstrators on Sunday attacked sushi restaurants or other businesses perceived to have a Japanese
connection. Several photographs said to be from Shenzhen, across the border from Hong Kong, showed what appeared to be damaged or overturned cars — most of them Japanese models — as well as several police
vehicles. The demonstrations appeared to be sanctioned and chaperoned by the police, who generally prohibit public protests unless they
suit the needs of the Communist Party. In the past, Beijing has allowed nationalist sentiment to bubble up into street demonstrations, but
the authorities usually keep them contained out of concern they might spiral out of control or turn into popular antigovernment sentiment. Even as the protests began unfolding Sunday morning, a group of conservative
Japanese activists might have planted the seeds for further anger in China. About 10 of the activists, including local assembly
members from Tokyo, swam ashore to the disputed island, Uotsuri. While Japan controls the island chain, the Tokyo government restricts
access to avoid inflaming regional tensions. The 10 who landed Sunday did so without permission, and were later questioned by the Japanese Coast Guard. Members of the group said they were responding to the pro-China activists’ landing, and they
urged Prime Minister Yoshihiko Noda to do more to defend the islands.