Demonstrators hold banners (territorial integrity and protection of Diaoyu Islands in Chinese) and chant slogans as they protest outside the Japanese embassy in Beijing on Setp. 13, 2012. [Photo/people.com]

Police in south China's metropolis of Guangzhou have detained 11 people who had allegedly smashed a Japanese-brand car, shop windows and billboards during anti-Japan protests on Sunday.

Police in Guangzhou, capital of Guangdong Province, made the announcement on Monday on its official account of Sina Weibo, a popular Twitter-like microblogging service.