Image caption The violence in Zhanaozen has threatened Kazakhstan's reputation for stability

Residents of an oil town in Kazakhstan where deadly riots took place last month will not be allowed to vote in parliamentary elections on 15 January.

Kazakhstan's Constitutional Council said it would be impossible to conduct the poll in Zhanaozen due to a state of emergency introduced during the unrest.

Sixteen people died and more than 100 were injured in clashes between striking oil workers and the police.

There is a strong security presence in the town.

On Wednesday President Nursultan Nazarbayev extended the state of emergency until the end of January.

The violence resulted from Kazakhstan's longest-running industrial dispute, between the state oil company, Kazmunaigas, and hundreds of its employees.

The workers have been on strike for better pay and conditions since May 2011.

The company says it has lost hundreds of millions of dollars in oil revenue.

On 16 December clashes broke out as government forces tried to clear the town square which the striking workers were occupying.

Eyewitnesses said the police opened fire on unarmed protesters, although the security forces argued that they had been forced to defend themselves.

Dozens of protesters have since been arrested on suspicion of organising the riots.

Human rights workers say some of them have been tortured in detention.

The move to cancel the parliamentary elections in Zhanaozen will deny about 50,000 electors the right to vote, reports suggest.

"This decision can only be based on fear that the party in power would receive absolutely nothing in a real vote," political analyst Aidos Sarym told Reuters news agency.