Sixteen prisoners died when they blew themselves up after an abortive attempt to break out of a jail in southern Kazakhstan, the Justice Ministry said Tuesday.
The ministry said in a statement that the alarm was raised early Monday morning, when a group of armed prisoners attacked jail guards at the AK-159/21 medium-security prison in the town of Balkhash. One guard died of gunshot wounds on the way to the hospital and two others were injured.
After the skirmish, the fugitives took refuge in a sewing factory on the premises of the jail.
Justice officials say the prisoners died when they detonated an oxygen canister as special forces approached the building.
However, the official account contained little detail, including what would have motivated the prisoners to take their own lives in such a way. Kazakh authorities' explanations for such events are often piecemeal and incomplete.
Authorities say the prisoners involved in the breakout were serving lengthy sentences for grave crimes, including robbery, murder and rape.
Local media reports cited a Justice Ministry official as saying one of the men was in jail for belonging to an extremist religious group.
The prisoners' ability to secure firearms will likely prompt concern over security in the former Soviet nation's jails.
Kazakhstan's prisons are reportedly overcrowded, and rights activists routinely complain about poor conditions for inmates. Senior U.N. human rights envoy Manfred Nowak in 2009 expressed concern over reports of widespread mistreatment of Kazakh prisoners.
Nowak also decried the lack of an effective complaints system and noted that many detainees refrain from airing their grievances for fear of reprisals.
Mass disturbances are a frequent occurrence in Kazakhstan's prisons.
Late last month, a riot broke out in a prison in a northern Kazakh town. Relatives of inmates say those involved in the unrest were subsequently badly beaten by prison officials.
In August 2010, two inmates were killed after police intervened at another prison in Kazakhstan's north to quell a mass brawl.
Authorities have attempted to address activists' criticisms by offering amnesties and granting parole to thousands of prisoners.