squad

団(だん)	An association or brigade... but usually used about volunteer groups such as volunteer fire-fighters, or Neighborhood Watch. Not to mention the 暴力団 (the newspaper/police word for yakuza).

隊(たい)	Squad – usually used with military (or marching band or fire-fighter brigade, or ambulance crew!)

団体(だんたい)	Any organization. Unlike the other ‘tai’, (隊), 団体 does not have any military feeling. $$$

部隊(ぶたい)	Military unit.

部(ぶ)	Xxx club.

班(はん)	Is a squad too, or a team or a task force or something