Amnesty International said on Friday the group Boko Haram killed at least 60 people last week in an attack on the northeastern border town of Rann in Nigeria. Witnesses told Amnesty International Nigerian military left the area the day before the attack, leading to an exodus of residents who feared attacks by Boko Haram. The U.N. says that tens of thousands of Nigerians fled to neighboring Cameroon in January. Boko Haram attacked Rann earlier in January, killing 14 people.