A few minutes; several minutes — a short duration on the order of minutes (e.g., two or three minutes).
すぐに戻るから数分待っていてください。
I'll be right back, so please wait a few minutes.
この作業は数分で終わるはずだ。
This task should be finished in several minutes.
電車は数分遅れて到着した。
The train arrived several minutes late.