A court in Kazakhstan has upheld the conviction of an opposition leader who was accused of inciting unrest and plotting to overthrow the government.

The court in the western city of Aktau ruled on Monday that Vladimir Kozlov, the leader of the Alga party, would have to face seven-and-a-half years in jail.

Kozlov had been sentenced last month for his alleged involvement in inciting rioting in the oil town of Zhanaozen in December.

The United States has denounced the ruling as an "apparent use of the criminal system to silence opposition voices".

State television aired a documentary on Thursday claiming Kozlov orchestrated the unrest in Zhanaozen, which stemmed from a labour dispute, to make money.

Source: Agencies