The US has announced that an elaborate spy swap with Russia has taken place successfully. Ten Russian agents arrested in the US last month were flown to Vienna and exchanged for four people who had been jailed in Russia. David Willis reports from Washington.

Shortly after private flights from Russia and America brought the spies to Vienna where they changed planes and then took off, the American Justice Department announced the biggest spy swap since the Cold War had been successfully completed. The American plane carrying four spies from Russia stopped briefly at a British air force base on its return to the US, and reports suggest two of the four may have got off there. Senior US officials have hailed the spy saga as an important achievement, saying that by shutting down the network, they have demonstrated strong counter-intelligence capability and sent a warning to other countries that might have been contemplating spying on the US.