Acting Umno president Mohamad Hassan today cautioned Umno leaders to be careful of what they say, particularly as the party prepares to face another by-election in Rantau.

While stressing that Umno will not issue a gag order against any member or leader, Mohamad, who has formally announced that he will re-contest the Negeri Sembilan state seat, said the leaders themselves should know better than to make remarks detrimental to BN or even the country.