BBC News with David Austin

China's best-known contemporary artist Ai Weiwei has been released after more than two months in police detention. Chinese state media said he had confessed to tax evasion and had promised to repay what he owed. Contacted by the BBC, Mr Ai said he was at home on bail and was well but couldn't talk any further to the media. Ai Weiwei, a vocal critic of the Chinese Communist Party, was seized by police at Beijing airport in April. Martin Patience reports from Beijing.

State media reported that Ai Weiwei had been released after showing what it called a "good attitude in confessing to his crimes" and also because he was suffering from a chronic illness. Ai Weiwei's detention came during the biggest crackdown against dissidents in China for over 20 years following calls for Middle East-style protests. Western leaders have said that his arrest was a sign of the deteriorating human rights situation in the country. Now he's been released, and it comes just days before China's Premier Wen Jiabao begins an official visit to Britain.

In a speech this evening, President Barack Obama is expected to announce a gradual withdrawal of thousands of American troops from Afghanistan. Early reports suggest they'll be withdrawn in phases with around 5,000 troops leaving within months. Jonny Dymond in Washington has more.

The enormous cost of the military deployment, currently more than $2bn a week, is attracting high-profile criticism from Republicans and Democrats whilst the public, battered by hard economic times, are weary of a war that seems to have no end and appears punctuated only by the deaths of young Americans. But the president cannot cut too deep or too fast. His military commanders are wary of throwing away hard-fought gains by withdrawing troops too soon.