What's been happening in Xinjiang?
Alistair Burnett, editor of The World Tonight, writes:
We know more than 150 people have been killed in violence in the regional capital Urumqi and we know there have been demonstrations by Uighurs - the ethnic Turkic Muslims who live in that part of China - and counter demonstrations by local Hans - the majority ethnic group in China. We also know the government have flooded the city with security forces to prevent further violence. But crucially we don't know exactly how it started and what happened when most of the deaths happened last Sunday.
The Chinese authorities say Uighur exile groups and radical islamists have been stirring up separatist violence. The Uighur exiles say Chinese security forces killed peaceful demonstrators protesting at the receent deaths of Uighurs in a brawl at a factory in southern China.
This is the worst case of unrest in China - certainly in terms of loss of life - since the suppression of the Tiananmen protests 20 years ago, so this week The World Tonight has given it a lot of coverage.
But it has been difficult to establish exactly what happened before the BBC Beijing Correspondent, Quentin Somerville , got to Urumqi on Monday.
We have spoken to the Uighur exile group the World Uighur Congress, who accused the Chinese security forces of killing hundreds of Uighurs. We have spoken to the Chinese Embassy spokesman in London, who accused extremist groups abroad of being behind the violence.
By Wednesday, we wanted to know how credible the accounts of the two sides are so we spoke to James Millward of Georgetown University, an expert on Xinjiang, who said they are both guilty of spinning - it's worth a listen.
(Broadcast on The World Tonight, BBC Radio 4, 8 July 2009)