Explosions heard in Ukraine capital Kyiv, Mariupol

Explosions were heard before dawn Thursday in Ukraine's capital Kyiv and the eastern port city of Mariupol, shortly after Russia's President Vladimir Putin announced an operation to "demilitarise" the country.

AFP correspondents in both cities heard powerful blasts and in Mariupol, close to the frontline and the Russian border, residents reported hearing artillery in the city's eastern suburbs.