Some of Japan’s most well-known companies shuttered their factories and stores across China on Monday as the country braced for the biggest anti-Japanese protests in years as tensions over disputed islands continued to escalate.

Authorities have warned Japanese businesses to suspend operations, with tens of thousands of Chinese expected to take to the streets on Tuesday, which also marks the sensitive 81st anniversary of the Japanese occupation of China - an event that still evokes strong passions here.

Japanese companies including Honda, Panasonic, Canon, Nissan and clothing retailer Uniqlo said they would close their factories and stores for a few days.

This followed protests in several dozen cities over the weekend. While protests in Beijing and Shanghai for the most part remained orderly amid a massive police presence, violence was reported in a number of cities, where Japanese restaurants were trashed, department stores ransacked and Japanese-branded cars torched by mobs.

A Panasonic factory in northeastern Qingdao was attacked, forcing the company to close operations on Tuesday. Honda and Nissan, the automobile giants, said they would suspend production for two days.

Clothing retailer Uniqlo, which is a popular brand in China, closed its flagship store in Beijing’s Sanlitun shopping district on Saturday. A crowd of protesters gathered in front of the store on Sunday night, calling on Chinese to boycott Japanese brands.

The Communist Party's official People's Daily warned in a commentary that Japan should prepare itself for "economic punishments". "Would Japan rather lose another 10 years, or even be prepared to fall back 20 years?", said the article, hinting that economic sanctions were not off the table.

While China is Japan's biggest trade partner, any slump in the US$ 345 billion trade is, however, also likely to impact Beijing amid a global slowdown that has hit its export industry.

Tensions between the two countries flared last week after Japan announced it would purchase three of the Diaoyu or Senkaku Islands from the family recognised by Tokyo as the owner. Beijing retaliated by dispatching six maritime surveillance vessels to patrol off the islands’ territorial waters.

After a series of commentaries appeared in State media outlets attacking Japan, crowds of protesters began to gather over the weekend, apparently with the tacit consent of local authorities who usually do not tolerate protests. The government has, however, presented itself a balancing act by stoking nationalist sentiment, with many protesters also voicing anger at a “weak” response from Beijing on the dispute.

In a reflection that the authorities appeared to have been caught off guard by the scale of the protests and the violence, the People’s Daily and other official media toned down their message on Monday, calling for “rational patriotism”.

“When the sovereign territory of the motherland is subjected to provocation, our anger is irrepressible and the enthusiasm of youth must have release,” the People’s Daily said in an editorial. “However, a civilized attitude abiding by rule of law should be the basic conduct of the citizenry. Doing damage to the legal property of one’s compatriots and venting anger on Japanese citizens in China is extremely inappropriate.”