Firefighters battled blazes in Odesa until early hours on Tuesday after Russian missiles pounded the Ukrainian port on the day President Vladimir Putin led celebrations in Moscow marking Soviet victory over Nazi Germany in World War II.

In a defiant Victory Day speech on Monday, Putin exhorted Russians to battle for their homeland but was silent about plans for any escalation. In Ukraine, there was no let up in fighting, with Russian strikes on targets in the east and south and a renewed push by Kremlin's forces to defeat the last Ukrainian troops holding out in a steelworks in ruined Mariupol.

At least 100 civilians remained trapped in the plant, which remained under heavy Russian fire, an aide to Mariupol mayor said on Tuesday.