According to the government source, the unrest was sparked by ______

Uzbekistan’s government said on Tuesday troops had killed "terrorists" not civilians to quell unrest, contradicting witnesses who said they shot hundreds of protesters, including women and children.
   An Uzbek opposition party said it had compiled a list of 745 people killed. Witnesses and a human rights activist in the eastern town of  Andizhan have put the death toll at about 500.
   The unrest, sparked by the trial of 23 Muslim businessmen and blamed by Karimov on Islamic extremists, was the bloodiest chapter in Uzbekistan’s post-Soviet history.
   Uzbekistan’ s prosecutor general said rebels killed 159 people, including three women and two children. It previously said 10 policemen were killed and "many more" rebels.
   Residents and a local human rights activist say the rebellion was staged by locals protesting against poverty, corruption and Karimov’ s hard line against Muslims.