Prosecutors in Uzbekistan say three law enforcement officers have been arrested in connection with an investigation into misconduct by government forces during the suppression of mass protests that shook the country’s autonomous republic of Karakalpakstan last summer.

This is the first known time that any non-civilians have been detained over the unrest, which left 21 people, including four law enforcement officers, dead. 

A vaguely worded statement posted online by the General Prosecutor’s Office on February 9 did not specify what criminal offenses the officers are alleged to have committed or provide any details about which force they serve in.

“Investigations are currently ongoing. Once the investigation is finished, the case will be transferred to the courts,” the statement read.

The possibility this might come to pass had been signaled in December, when prosecutors pledged that they would conduct what they termed “a legal assessment” on the use of live firearms by security forces during the turmoil in the city of Nukus in July. Human rights groups have argued that the deployment of live weapons and powerful stun grenades constituted an overly heavy-handed response and led to gruesome injuries and deaths.

The thousands of people who took to the streets of Nukus in early July had done so in a mass gesture of opposition to planned constitutional changes that would have further diluted Karakalpakstan’s already nominal autonomy. In an apparent admission that the mooted reform was a miscalculation, President Shavkat Mirziyoyev quickly scrapped the proposed amendments after the unrest subsided, although he also blamed “hostile outside forces” for stirring up the trouble.   

It is only demonstrators who have been put through the justice system so far.

Last month, a court in Bukhara found 22 people guilty on various counts over their involvement in the turmoil. The heaviest punishment, 16 years in prison, was reserved for Dauletmurat Tazhimuratov, a Nukus-based lawyer and activist the authorities claim led the uprising. Another man, a former police officer, died of heart failure days after he was sentenced. A second trial, in which 39 defendants are in the dock, started last week. The accused in that trial face charges ranging from rioting and vandalism to grievous bodily harm and the dissemination of separatist propaganda.