Kazakhstan’s former Commander-in-Chief of the Naval Forces has been detained as part of a criminal investigation into the deaths of servicemen during military exercises in the Caspian Sea.

Military investigators detained the former naval chief, a first-rank captain, and placed him in a temporary detention facility on charges of negligent performance of duty, Qazinform reports.

A court later authorized his arrest. The pre-trial investigation is ongoing.

The incident occurred on September 24 during the Khazar Qorgany 2026 naval exercises off Kazakhstan’s Caspian Sea coast. A sudden deterioration in weather and strengthening winds swept 19 servicemen into the sea.

Kazakhstan’s Prime Minister Olzhas Bektenov ordered the creation of a government commission to investigate the deaths in the Mangistau region. The Defense Ministry later released the names of 12 servicemen killed during the exercises.

President Kassym-Jomart Tokayev expressed condolences to the families of the servicemen who died. September 25 was declared a national day of mourning in Kazakhstan.

The Khazar Qorgany 2026 exercises began on September 22 in Kazakhstan’s sector of the Caspian Sea and involved more than 500 military personnel, naval ships and boats, hydrographic vessels, Coast Guard units of the National Security Committee’s Border Service, and Air Defense Forces aircraft.

Kazakh prosecutors have also identified suspects in the criminal investigation into the deaths on the Caspian coast.