By Anna Koper and Olimpiu Gheorghiu PRZEMYSL, Poland/PALANCA, Moldova (Reuters) -Nearly three weeks into the war, the number of Ukrainians fleeing abroad approached 3 million on Tuesday, the United Nations said, as people escaped fighting and Russian bombardment. About 2.95 million people have so far left Ukraine, data from the U.N. Refugee Agency (UNHCR) showed. It is basing its aid plans on 4 million refugees but has said the figure will likely increase. After Sunday’s Russian strike on the Yavoriv military base near Lviv, some people from western Ukraine have now joined the refugee flow acr…