A suicide bomber blew himself up on Tuesday outside a regional security building in the western Kazakh city of Aktyubinsk, a police source said.
Only the bomber was killed in the attack.
A spokesman for Kazakhstan's Prosecutor General's Office said it would hold a news briefing in a few hours.
Terrorist attacks are rare in the Central Asian state, which has been ruled by the former Soviet-era leader Nursultan Nazarbayev since independence in 1991.
ASTANA, May 17 (RIA Novosti)