BEIJING - There have been more calls both on- and off-line for rational expressions of patriotism as protests against Japan's purchase of the Diaoyu Islands continued into Sunday, drawing participants in more Chinese cities.

In Guangzhou, capital of the southern province of Guangdong, over 10,000 people marched along several streets before staging protests outside the hotel housing the Japanese consulate on Sunday morning.

People urging protestors to refrain from violence could be heard amid the flag-waving and slogan-chanting crowd, and police used outdoor public broadcasting systems to warn protestors against committing crimes.

Authorities in major Chinese cities also beefed up security efforts to prevent violent protestors from damaging property.

Guangzhou authorities said they sent more police to guard Japanese businesses and the hotel housing the Japanese consulate along the protest route on Sunday.

The demonstration in Guangzhou ended at about 1 pm, though some protestors lingered for some time before being dispersed by police.

In Haikou, capital of South China's Hainan province, 2,600 police officers were dispatched to the site where nearly 4,000 people staged a protest at 9 am.

Mass protests were also seen in cities such as Xiamen, Hangzhou, Harbin, Nanjing, Hohhot, Changchun and Wuhan. Xinhua reporters said protests were largely peaceful, with few incidents of looting and car smashing.

Many protestors said they were responding to calls posted on online forums or QQ, a popular messaging service, while some others were organized by companies and social groups.

Large police presences could be seen maintaining order at all the protest sites, while some restaurants and stores selling Japanese products closed and hung up Chinese national flags as protestors neared.