MOSCOW—A Russian warplane crashed into the sea on Monday during a training mission in southern Russia and its pilot died after bailing out, authorities said.

The regional administration of the Krasnodar region said that the Su-25 ground attack jet crashed into the Sea of Azov. It said that pilot ejected and was evacuated by emergency teams, but Roman Bublik, the mayor of town of Yeysk, later said that he died.

The Russian military said engine failure had caused the crash.

Russian media carried a video of the plane falling into the sea just off a crowded beach on the Yeysk Spit.

The Su-25 is a twin-engine ground attack aircraft that has been in service with the Soviet and Russian air forces since 1980s. It has been used extensively during Russia’s action in Ukraine.

The Russian air force has suffered a string of crashes that some observers have attributed to a higher number of flights amid the fighting in Ukraine.