The siege at a college in northeast Kenya is finally over, but the death toll has risen to at least 147, reports Reuters. The vast majority of victims were believed to be students at Garissa University College. Authorities say that four gunmen, believed to belong to the al-Shabab extremist group from neighboring Somalia, also are dead, reports AP. They reportedly stormed the school's dormitories this morning and began separating students into Muslim and non-Muslim groups, reports the New York Times. Kenyan security forces eventually launched a raid to free the hostages, and it remains unclear exactly how all the victims died. The death toll far surpasses the 67 who were killed in al-Shabab's attack on Nairobi's Westgate Mall in 2013. (More Kenya stories.)