Nine servicemen have reportedly died after being swept into the Caspian Sea during military exercises in Kazakhstan’s Mangystau Region.

Kazakh blogger Azamat Sarsenbayev from Aktau published video footage from the scene of the incident, NUR.KZ reports.

The incident occurred on September 24 during exercises involving the Naval Forces of Kazakhstan’s Armed Forces. According to the Ministry of Defense, a sudden deterioration in weather conditions and strong winds swept 19 servicemen into the sea while they were carrying out a training combat mission along the Caspian coast.

The Defense Ministry said nine servicemen have so far been confirmed dead.

Three servicemen were rescued, including one who was hospitalized. Search operations are continuing for those still missing.

Kazakhstan’s Prosecutor General’s Office said a criminal case has been opened and is being investigated over the deaths of servicemen during the exercises at the Aktau garrison.