ABUJA, Nigeria - Nigeria is opening a secret detention center to hold and interrogate suspected high-level members of a radical Islamist sect responsible for hundreds of killings this year alone, a security official has told the Associated Press.

While the facility could create a more cohesive effort among disparate and sometimes feuding security agencies in Nigeria to combat the sect known as Boko Haram, it raises concerns about its possible use for torture and illegal detentions. Nigeria's security forces have notorious human-rights records, with a documented history of abusing and even killing prisoners.

In Maiduguri, meanwhile, where Boko Haram once had its main mosque, gunmen suspected of belonging to the sect attacked a bakery and shot others in the streets, killing at least seven people, police said Thursday.

The new detention center is in Lagos, far from the violence plaguing the country's predominantly Muslim north, where Boko Haram carries out frequent bombings and ambushes, said the security official, who is directly involved in the project. He spoke on condition of anonymity because he was not authorized to discuss the facility with journalists.

"All suspects arrested will be taken to the center and would be interrogated by a security group," the official said. He declined to say exactly where it is or how many inmates it can hold.

The detention center was created at the orders of Nigeria's national security adviser, Gen. Andrew Owoye Azazi, the official said. Azazi's telephone number is unlisted and the AP was unable to contact him for comment.

Ekpeyong Ita, the director-general of Nigeria's secret police agency, known as the State Security Service, declined to comment Thursday when the AP asked him about the prison. Minutes later, secret police spokeswoman Marilyn Ogar called an AP journalist and said anyone with information about the purported prison should go to the courts instead of talking to journalists. She refused to confirm or deny the prison's existence.