Russian President Mr Vladimir Putin held a crisis meeting today in Moscow and issued instructions to be followed in connection with attacks on US targets, a Kremlin spokesman said.
NATO evacuated its Brussels headquarters after the attacks in New York and Washington as Secretary General Mr George Robertson called on alliance forces to unite against terrorism.
"I condemn in the strongest possible terms the senseless attacks which have just been perpetrated against the United States of America," Mr Robertson said in a statement.
"My sympathies go to the American people, the victims and their families," he said.
An emergency meeting of EU foreign ministers has been called for tomorrow morning in Brussels.
Britain has also heightened its state of alert at government buildings and at diplomatic posts worldwide, Foreign Secretary Mr Jack Straw announced.
He said the alert states at British diplomatic posts abroad had been raised to their highest level, and British citizens in sensitive areas had been told to exercise caution.
The British move was followed by China, which stepped up security outside the US embassy in central Beijing.
But there was no immediate official reaction from the Chinese government to the attacks, although a foreign ministry spokeswoman said it would follow "soon".
AFP &