Hi Berni,
My Sak and Lazarski ancestors come from Bakalarzewo area of Poland. It's now in the north east section and has always been considered part of Poland by the people even during the partitions. The Sak family had an immigrant to Michigan in the 1900s and the Lazarski family had a daughter immigrate to Wisconsin in the 1890s. I don;t think there's a connection with your Belarus family - at least from the mid 1800s. Let me know, though, if you find any other info that might link them.
bob