Kazakh authorities say a man blew himself up today outside the regional headquarters of the security service in the northwestern city of Aqtobe, injuring at least two people.
Officials said no one other than the bomber was killed in what is the first known suicide bombing in the oil-rich country.
The man has been identified as 25-year-old Rakhimzhan Makhatov, the Prosecutor-General's Office told a press briefing in the capital, Astana.
Spokesman Zhandos Umiraliev said he did not believe the incident was an act of terrorism.
He said Makhatov was a member of an organized criminal group and was suspected of having committed a number of crimes.
"Makhatov used a homemade, low-power explosive device," Umiraliev said. "As a result, Makhatov died on the spot. Two people standing next to him received minor injuries. They have received medical treatment."
News agencies earlier reported that a 32-year-old business executive was seriously injured by the blast and was taken to hospital unconscious, but this has not been confirmed.
Alima Abdirova, RFE/RL's Kazakh Service correspondent in Aqtobe, said police have cordoned off the area. She said officers are not allowing anyone, including journalists, near the area around the security services' headquarters and the regional center of the Interior Affairs Department, in the old part of the city.
She added that several journalists, along with political and human rights activists, took photos at the scene but that police officers erased the images from their cameras.
"A police officer said it was a kind of training exercise, and that there wasn't any blast," Abdirova said. "This is how he explained the incident to me. The press office of the regional Interior Affairs Department said it had nothing to do with them."
Abdirova, however, said it would be highly unusual for a regular training exercise to be surrounded by so much secrecy, saying they are typically announced in advance.
Taxi drivers told her they saw ambulances and fire engines arriving in the area.
A cameraman for a local television channel was briefly detained by police while trying to film the scene of the blast from a hotel across the street. Nurken Zhalmakhanov was later released.
In the first international reaction to the Aqtobe blast, the current chairman of the Organization for Security and Cooperation in Europe, Lithuanian Foreign Minister Audronius Ažubalis, condemned what he called "this terrorist act."
Kazakhstan has so far avoided outbreaks of violence that have occurred in neighboring Kyrgyzstan, Tajikistan, and Uzbekistan.
written by Farangis Najibullah in Prague, based on reporting by RFE/RL's Kazakh Service and agency reports