Top U.S. diplomat visits troubled Central African Republic Samantha Power authored a book about the U.S. response to genocides Amnesty International says war crimes and crimes against humanity are being committed Human Rights Watch report documents violence around the northern town of Bossangoa The violence is fueling "enormous anger, hostility and mistrust," says one expert (CNN) -- A top U.S. diplomat known for her expertise in genocide arrived in the violence-wracked Central African Republic on Thursday to gauge the growing sectarian unrest there between Christians and Muslims. Samantha Power, the U.S. ambassador to the United Nations, is leading a delegation to Africa, first visiting the Central African Republic, and then off to Nigeria and Chad. "Here to meet people of #CAR and assess the crisis firsthand ...," she tweeted. An expert on the issue of U.S. politics and genocide, Power is well-positioned to understand and respond to the outbreak in violence. She authored " 'A Problem from Hell,' America and the Age of Genocide." That 2002 book examines the U.S. reactions to genocides. The Central African Republic has seen violence and chaos since the Muslim-backed Seleka militia and other rebel groups from the marginalized northeast seized the capital, Bangui, in March. The U.S. mission at the United Nations said Power is meeting with government, U.N., French and other officials, "to assess and support recent efforts of African Union and French forces to protect civilians, stabilize the country and restore humanitarian access." In Nigeria and Chad, she'll be meeting with officials "to discuss cooperation on a range of issues from promoting human rights and good governance to coordinating on regional security." Nigeria and Chad are joining the U.N. Security Council as nonpermanent members in 2014. Power's delegation includes Assistant Secretary of State for African Affairs Linda Thomas-Greenfield The surge of sectarian violence has been well-documented, and rights activists are urging quick and tough action to stop the violence. War crimes reported Amnesty International said former rebels in the Central African Republic killed almost 1,000 people in a two-day rampage this month. War crimes and crimes against humanity are being committed in the country, Amnesty International said. "Crimes that have been committed include extrajudicial executions, mutilation of bodies, intentional destruction of religious buildings such as mosques, and the forced displacement of massive numbers of people," said Christian Mukosa, Amnesty International's Central Africa expert. They mainly targeted Christian communities, which in turn formed their own vigilante group, the anti-balaka (literally "anti-machete"). Anti-balaka forces staged an early morning attack in the capital on December 5, going door to door in some neighborhoods and killing approximately 60 Muslim men, Amnesty International said. De facto government forces, known as ex-Seleka, retaliated against Christians, killing nearly 1,000 men over a two-day period, according to the rights group. A small number of women and children also were killed. In a statement, Amnesty International called for the deployment of a "robust" U.N. peacekeeping force, with a mandate to protect civilians, and enough resources to do so effectively. "The continuing violence, the extensive destruction of property, and the forced displacement of the population in Bangui are feeding enormous anger, hostility and mistrust," said Mukosa. There can be no prospect of ending the cycle of violence until the militias are disarmed and there is proper and effective protection for the thousands of civilians at risk in the country. Residential neighborhoods must be made safe as an urgent priority in order to allow people to go back to their homes and resume their normal lives. Violence in Bossangoa In a separate report, Human Rights Watch cited a surge in violence around the northern town of Bossangoa since September, adding that concerned countries should immediately bolster the African Union peacekeeping force in the country and support efforts by France to protect civilians. In the report, Human Rights Watch said Christian militias attacked Muslim communities, cutting the throats of children while forcing parents to watch. Muslim groups retaliated, setting fire to Christian homes and killing their occupants with the apparent approval of commanders present, Human Rights Watch said. The recent violence has created a humanitarian crisis. Both sides have burned down large swaths of villages in the northern Ouham province, the rights group said, adding that relief workers have found it difficult to provide help, particularly emergency medical aid, as aid workers have also been the targets of attacks. "The brutal killings in the Central African Republic are creating a cycle of murder and reprisal that threatens to spin out of control," said Peter Bouckaert, emergencies director at Human Rights Watch and author of the report. The UN Security Council needs to act quickly to bring this evolving catastrophe to a halt. The Central African Republic is about the size of France and is rich in resources, including diamonds, gold, timber and ivory. The former French colony has rarely seen political stability or economic growth in the 53 years since it gained independence. CNN's Susanna Capelouto and Dana Ford contributed to this report.