MOSCOW, November 19 (RIA Novosti) - A Russian frigate will join the search for a Russian cargo vessel that has been missing in the Caspian Sea since Saturday morning, a Navy spokesman said Monday.

The Kamyust-1 cargo ship, sailing under a Russian flag, en route from Astrakhan to the Iranian port of Enzeli, sent a distress call at about 11:00 a.m. Moscow time (8 a.m. GMT) on Saturday.

There are 12 crew members on board the ship carrying 2,200 metric tons of steel feed.

"Missile frigate Tatarstan, the flagship of the Caspian Flotilla, has joined the rescue operation about 115 miles east of Makhachkala [Russian port on the western shore of the Caspian Sea], following a request by the Astrakhan regional maritime rescue center," Igor Drygalo said.

A Russian coast guard corvette and eight other ships have already been involved in the joint rescue operation conducted by emergency services from Russia, Kazakhstan and Iran since Saturday.