Two missile boats, Paykan and Joshan, and the Damavand destroyer, left Iran's Bandar-e Anzali port earlier this week. The missile boats plan to remain moored in Astrakhan until Friday evening.
According to a spokesman for the southern military region, the Damavand destroyer remained in the Caspian Sea, unable to make the journey north due to the low water level of the River Volga, and will rejoin the missile boats when they return to the sea for training.
Following the exercises, the Iranian fleet will continue its journey with a visit to Baky, Azerbaijan.
The missile boats Paykan and Joshan previously visited Astrakhan in 2013. The Damavand, Iran's newest destroyer, joined its fleet in March 2015, and took part in joint training with Russia's Caspian Sea fleet at Bandar-e Anzali in August.