‘Tanks in streets’ as fighting hits Mariupol centre

Mariupol has seen some of the fiercest battles since Russia invaded Ukraine, three weeks ago. The location of the port city, on the Sea of Azov, is strategic for Russia, as it would help it create a land corridor between the eastern regions of Donetsk and Luhansk, controlled by Russian-backed separatists, and Crimea, the peninsula it invaded and annexed in 2014.