Let R be a commutative ring with identity. A proper ideal P of R is an (n - 1, n)-Fm-prime ((n - 1, n)-weakly prime) ideal if a1, … , anÎR, a1 … anÎP\P m (a1 … anÎP\{0}) implies a1 … ai-1 ai+1 … anÎP, for some iÎ{1, …, n}; (m, n³2).In this paper several results concerning (n - 1, n)-Fm-prime and (n - 1, n)-weakly prime ideals are proved. We show that in a Noetherian domain a Fm-prime ideal is primary and we show that in some well-known rings (n - 1, n)-Fm-prime ideals and (n - 1, n)-prime ideals coincide.