Crumbling community trust in Kyrgyzstan
The referendum being held in Kyrgyzstan on a new constitution comes amid fears it could inflame ethnic tensions. The BBC's Rupert Wingfield Hayes has just left Kyrgyzstan and explains the background to the country's current difficulties.
When southern Kyrgyzstan erupted in to violence two weeks ago the outside world was taken by surprise.
But those watching more closely were much less surprised. It had, they say, been brewing for months.
Others say it has been brewing for 20 years, ever since the collapse of the Soviet Union.
The countries that we today collectively call the Central Asian "Stans" were created by Soviet planners back in the 1920s.
They were carved out of a vast swathe of territory known in the Russian empire as "Turkestan".
Between 1924 and 1927 it was divided into five republics: Uzbekistan, Kazakhstan, Turkmenistan, Tajikistan, and Kyrgyzstan.
Such divisions were artificial and deliberately ignored smaller ethnic groups like the Sarts, Kipchaks and Karakalpaks - to name a few.
Right in the heart of this newly divided territory lies the broad expanse of the Ferghana Valley.
It is not really a valley, more a large fertile basin, 300km (185 miles) long, by 70km (45 miles) wide.
It is surrounded on three sides by high snow capped mountains: the Heavenly Mountains (Tian Shan) to the north and east, and the Pamirs to the south.
The Ferghana is lush, its climate warm, its fields of rice and potatoes well watered by the snow melt from the mountains above.
After the Soviet carve-up, most of the Ferghana ended up in Uzbekistan.
But pockets of territory also ended up in Tajikistan in the south, and Kyrgyzstan in the east.
The cities of Jalalabad and Osh, with their large Uzbek populations, were left on the Kyrgyz side of the border.
None of this was much of a problem as long as they all remained inside the Soviet Union.
But the collapse of the Soviet empire in 1991 led to a rapid reassertion, some might say re-invention, of national identity.
Uzbekistan built its new national myth around the figure of Tamerlane, better known as "Timur the Great".
Born in 1336, Timur conquered much of central and west Asia, and built an empire that stretched from the Indus River to the Black Sea coast.
Kyrgyzstan's national myth is built around a much less well know figure: Manas. He is the hero of an epic poem, claimed by some to be 1,000 years old and the longest ever written.
Whether Manas actually ever existed is a rather moot point.
Caught between these two newly assertive nation states are the peoples of the border lands.
In 1990, as the Soviet Union teetered on the edge of collapse, violence erupted in Osh.
The immediate spark was a dispute over land. But beneath it ran a deep current of ethnic tension.
Uzbek community leaders wanted their own autonomous region in southern Kyrgyzstan, recognition of the Uzbek language and government jobs.
To the Kyrgyz majority the Uzbeks represented a fifth column, intent on breaking away and joining newly independent Uzbekistan.
Moscow sent troops, the violence ended, stability returned. But 20 years later it is back.
This time it began with the April overthrow of President Kurmanbek Bakiyev.
In the political void left behind different groups have been clamouring for power and advantage.
In Osh, local Kyrgyz officials claim that Uzbek nationalists immediately began agitating.
One figure in particular stands out, a local millionaire Uzbek businessman called Kadijan Batirov.
Kyrgyz officials claim Mr Batirov took to the airwaves broadcasting on Uzbek language TV.
The demands, they say, were the same as 20 years earlier: autonomy, Uzbek language, government jobs.
This in itself hardly seems enough to provoke the violence that ensued.
But there were other factors too.
Go to Osh and it is obvious the Uzbek community is considerably wealthier than the Kyrgyz.
Historically they are traders and farmers. Many of the bazaars, shops and restaurants in the city are Uzbek-owned.
Their houses are large, many drive German cars.
The Kyrgz are traditionally pastoralist. They have not done well in the post-Soviet economy - 800,000 Kyrgyz men, many from the south, have left to work in Russia.
You can find them cleaning the streets and on the building sites of Moscow.
There is also clear evidence that the violence was organised.
The Kyrgyz interim government has released telephone recordings it says are of the former president's son plotting to stir up ethnic violence.
In them a voice, claimed to be that of Maxim Bakiyev, can be heard discussing the hiring and arming of groups of young men.
Kyrgyz colleagues who have listened to the tape say they are certain the voice is his.
Maxim Bakiyev - currently seeking asylum in the UK - has denied the allegations in a statement released through his lawyers.
"The charges are bogus, to divert attention from their own crimes," the statement said.
Mr Bakiyev said there had been no opportunity for an investigation and that he was being made "a scapegoat for the chaos in the country".
That the violence which began on 10 June was organised appears in little doubt.
Whoever threw the first stone - and there is some evidence that it was a group of Uzbek youths - most of the ensuing violence was directed against the Uzbek community.
In burned-out Uzbek neighbourhoods I found the brass casings from military issue AK47 rounds.
I was shown much larger rounds that locals say came from armoured vehicles.
The Uzbeks I spoke to say it is evidence the Kyrgyz military was directly involved in the killings. The Kyrgyz authorities say the guns and armoured vehicles were stolen.
Whatever the truth, the little trust that once existed between the two communities is now gone.
It is not unlike what happened in Northern Ireland in the 1960s. The police force and the ranks of the military are filled almost entirely by ethnic Kyrgyz. To the Uzbeks they are part of the problem, not the solution.
This weekend's referendum may help to bring stability back to Kyrgyzstan. A new government, with a popular mandate, can fill the power vacuum that has existed since April.
But in the current situation it is easy to understand why the Uzbek population of Osh and Jalalabad wants a return of Russian troops.
The old colonial master may have created the problem, but now it is the only one that both communities trust.