MANITOWOC, Wis. (WHBL) - There were arrests in Two Rivers and Sheboygan last night in the wake of a drug bust in the city of Two Rivers.  Authorities said they had been conducting controlled buys of heroin, and arrested two young men and a woman in Two Rivers.  They then identified a large heroin source in Sheboygan that was supplying the drug and arrested a 31 year old man and 22 year old woman in Sheboygan County.  In all, officers confiscated a quarter pound of heroin with an estimated street value of 10 to 12-thousand dollars.