The incident occurred with less than a minute left in the Hawks' 111-102 win over the Knicks.
The players are suspended without pay.
Marvin Williams will miss the Hawks' next two games against the Dallas Mavericks on Saturday and the Toronto Raptors on Wednesday. Shawne Willliams will serve his one game suspension on Sunday against the Detroit Pistons.
(Reporting by Mike Mouat in Windsor, Ontario; Editing by Peter Rutherford)