Nigeria is to investigate reports of rapes, child trafficking and other abuses in camps for people fleeing from the militant Islamist group Boko Haram.
The country's National Emergency Management Agency (Nema) has formed a panel to investigate the abuses.
A spokesperson for Nema told the BBC that investigators would visit every camp for displaced people.
Approximately 3.2 million Nigerians have fled their homes to escape Boko Haram's insurgency in the northeast.
Nema's investigation is a response to a report published by Nigeria's Calabar-based International Centre for Investigative Reporting (ICIR).
The report, written by freelance journalist Charles Dickson, alleges that hundreds of young girls have been trafficked from internally displaced persons (IDP) camps.
Many victims were from unregistered, makeshift camps established when official camps could no longer cope, the report says.
It quotes an unnamed nurse as saying many children were brought to her hospital after being raped in the IDP camps.
It also alleges refugees are being sold as unpaid domestic workers, raped repeatedly, and in some cases burned and wounded with knives.
A spokesperson for Nema told the BBC that the allegations were "very grievous".
Ezikial Manzo said that the report published by the ICIR was the first Nema had heard of abuses at the camps and that its panel would "do everything in their power" to investigate.
Mr Manzo said that representatives from the ICIR had been invited to join the investigators as they toured the camps. He was not able to say how many camps there are, as many have been set up unofficially to cope with the millions of refugees.
Nigeria's Independent National Electoral Commission estimates that 3.2 million people have been displaced by Boko Haram's insurgency in the country's northeast, 1.6 million internally and 1.6 million in neighbouring Chad, Cameroon and Niger.
BBC Nigeria analyst Jimeh Saleh says Nema's decision to launch the investigation is significant as the allegations are extremely serious.
Many people do not report rape in Nigeria, and have little confidence in the police to investigate cases, he says.
They will be hoping that Nema's investigation will be credible, and help break the culture of silence around rape, our reporter adds.
Nema has given the investigators two weeks to compile their report.
Nigeria's upcoming general election, due to take place on 14 February, has been postponed until 28 March due to security concerns.
Government officials said the country's military would be unable to provide sufficient security for the poll due to the Boko Haram insurgency.