Kazakhstan has invited the UN to take part in an inquiry into deadly riots in an oil-rich region where security forces are suspected of shooting and torturing protesters.
The head of the state energy company has been replaced, according to Russian news reports.
Tension spread to Aktau, capital of the western Mangistau region, after at least 16 people were reported killed in the nearby town of Zhanaozen, where oil workers have been involved in a long-running dispute.
Police have been accused of firing at protesters and beating them as they lay on the ground. The Kazakh authorities have blamed criminals and hinted at outside interference.
There have been complaints that local people benefit little from the petro-dollars that drive Kazakhstan’s economy.
Beyond the region, analysts say pressure has been mounting on President Nazarbayev to relax his authoritarian rule in the former Soviet republic.