At least 10 people have been killed in violent clashes between police and demonstrators in an oil town in western Kazakhstan where workers have been protesting for higher wages.
The mayor's office, a hotel and vehicles were set on fire in Zhanaozen, a city of 90,000 people in the south-west, said prosecutor-general Askhat Daulbayev.
The clashes appear to be some of the largest unrest to hit the former Soviet republic since it gained independence in 1991.
Contradictory accounts have emerged as to what set off the confrontation.
Mr Daulbayev said police were attacked as they sought to quell a disturbance in the city centre and were forced to fire on protesters. He said 10 people were killed.
Roza Teletayeva, who said she was a former oil worker dismissed in June for taking part in a strike, said a peaceful meeting of several hundred demonstrators was surrounded by police. "We were just standing peacefully and doing nothing," she said.
Ms Teletayeva said police opened fire on the crowd and that she had seen at least five people who had been killed. She said groups of angry young men later marched on the mayor's office and set it ablaze.
Footage broadcast on satellite TV showed men in workers' outfits charging a stage built for festivities to mark the 20th anniversary of Kazakhstan's independence.
Mr Daulbayev said the headquarters of OzenMunaiGaz oil company, where the demonstrators were formerly employed, was also set alight.
A team of interior ministry investigators has flown to the town to identify and punish the organisers of the unrest and restore order, Mr Daulbayev added.