Guatemalan citizens Esperanza Cardo-na-Arana and her daughters Oldin Edilsa Garcia-Cardona and Azucely Noemi Garcia-Cardona petition for review of an order of the Board of Immigration Appeals (BIA), which affirmed an immigration judge’s denial of their application for asylum. 1 We conclude that substantial evidence supports the BIA’s determinations that petitioners had not sufficiently established past persecution or a well-founded fear of future persecution. See Malonga v. Holder, 621 F.3d 757, 766 (8th Cir. 2010) (threats that are non-specific or lacking in immediacy do not support finding of persecution; harm arising from general conditions such as civil war or mob violence will not ordinarily support claim of persecution); Cubillos v. Holder, 565 F.3d 1054, 1057-58 (8th Cir. 2009) (threats in form of two anonymous phone calls and two anonymous letters over 4-year period, without more and in absence of evidence of who was responsible and their motives, were not sufficiently severe to constitute past persecution or to be objectively reasonable grounds for well-founded fear of future *608 persecution); Khrystotodorov v. Mukasey, 551 F.3d 775, 781 (8th Cir. 2008) (denial of asylum is reviewed for substantial evidence). In addition, we conclude that it is unnecessary to review the remaining issues raised by petitioners.

Accordingly, we deny the petition. See 8th Cir. R. 47B.