LVIV, Ukraine (Reuters) - About 20,000 civilians have managed so far to leave the besieged port city of Mariupol in private cars, Interior Ministry adviser Vadym Denysenko said on Wednesday.

       Mariupol residents have been trapped in the city by Russian shelling without heating, electricity and running water for most of the past two weeks, Ukrainian officials say. At least 200,000 are in urgent need of evacuation, according to official Ukrainian estimates earlier this week.

       (Reporting by Natalia Zinets, Editing by Timothy Heritage)