(Reuters) – The Russian defence ministry on Saturday announced it had cleared the entire urban area of Mariupol of Ukrainian forces and said only a few fighters remained in the Azovstal steelworks, the scene of repeated clashes. In an online post, the ministry said that as of April 16, Ukrainian forces in the besieged port city had lost more than 4,000 people, RIA added. Russian forces have been trying for several weeks to take the port, which is on the Sea of Azov, a body of water to the northeast of the Black Sea. “The entire urban area of Mariupol has been completely cleared … remnants of…