Russian missiles pounded Ukraine's Black Sea port city of Odesa on Friday, killing more than a dozen people including rescue workers in an attack President Volodymyr Zelensky described as "vile".

AFP journalists on the scene saw bodies covered by blankets strewn on the street, while images from officials showed exhausted emergency service workers smeared with blood and dirt dousing flames and treating wounded colleagues.

Local authorities said Russian aerial bombardments struck residential buildings, ambulances and a gas pipeline, leaving at least 20 people dead and wounding another 73 people, including rescuers.

Maria Slyzovska, who witnessed the attack, said the first strike rocked her mother's home leaving "everything broken" before the second missile hit.

"There were a lot of people there. There was blood and ambulances. We all live in the realities of this Russian roulette," she told the media.

Zelensky said Russian forces had launched a type of attack known as a double-tap strike on the port hub, with the second projectile ploughing into rescue workers at the scene.

City officials said Moscow targeted Odesa with Iskander missiles launched from the Crimean peninsula, annexed by Russia in 2014.

"Russian terror in Odesa is a sign of weakness of the enemy, which is fighting Ukrainian civilians at a time when it cannot guarantee security for people on its own territory," said presidential aide Andriy Yermak.

Agence France-Presse