China has told police to ensure stability as its economy slows, Japan's No.3 bank sought to beef up its depleted capital and markets fretted about the stricken US car industry.

European Central Bank President Jean-Claude Trichet said the deep financial crisis marked the first time since World War II that the finances of the industrial world have been at stake.

He said it could be solved by central banks and governments in concert, with a key role for the private sector, but told Sky Television: "It will take time."

The Bank of England seemed to share his view. Minutes of its last meeting, when it cut interest rates by a shock 1.5 percentage points, showed it considered an even bigger reduction to tackle a recession that has now been confirmed.

Rioting involving thousands of people exploded on Monday in China's Gansu province, the latest bout of popular unrest.

The China Daily quoted Public Security Minister Meng Jianzhu as saying police "should be fully aware of the challenge brought by the global financial crisis and try their best to maintain social stability".

Although the Gansu violence was triggered by a plan to resettle residents in an earthquake-torn region, it follows strikes by taxi drivers and labour protests in regions long-reliant on the Western world's demand for Chinese exports.

IMA Asia, a business intelligence provider, said it had raised its political risk rating for China from low to medium.

"We are concerned about the potential for unrest within a massive pool of migrant workers who face lay-offs in the construction and export manufacturing sectors," it said. Japan's third-largest bank, Sumitomo Mitsui Financial Group, followed the lead of its larger peers by planning to raise at least €2.3 billion via preferred securities to beef up a capital base rocked by rising bad loans.

Once thought to be relatively unharmed by the global credit crisis, Japanese banks are now scrambling to raise cash as recession and plunging domestic stocks sap their capital.

The head of Nomura, Japan's biggest brokerage, said he thought the global liquidity crisis was over but that the real economy was now the problem.