Amnesty International and seven other human rights organizations said, in a letter to U.S. President Barack Obama, that they had "serious" concerns about allegations raised in a series of articles about the CIA's work in Somalia.
They allege the CIA was involved "in detention, interrogation and transfer operations in Somalia that may violate domestic and international law."
The letter points to a July article in The Nation and an August article in The New York Times that alleges the CIA is involved in the interrogation of detainees in Somali using techniques that are questionable and potentially unlawful.
They point to a 2009 executive order from Obama that requires the CIA to avoid such activity and further obligates the U.S. government to uphold its treaty obligations regarding torture and other international human rights issues.
Clara Gutteridge, an official at British rights group Reprieve, told the BBC this month that she had evidence from "multiple, concurrent sources" that the CIA was running a secret detention center under the presidential compound in Mogadishu.
Somali Prime Minister Abdiweli Mohammed Ali told the BBC the reports weren't credible but said Washington was helping to "improve the security situation in the country."
The letter to Obama states that "the United States and its officials may be liable for the unlawful actions of individuals, groups, or foreign states acting under its control, or for knowingly assisting in or conspiring to commit such unlawful actions."