Nigeria has uncovered a spy cell run by militant Islamist group Boko Haram at the international airport in the capital Abuja apparently aimed at selecting targets for attack, the country's national security agency said.

In a statement, the Department of State Services (DSS) said it discovered the ring last week and was working with aviation authorities to pre-empt any attack. The DSS said it had arrested a 14-year-old boy who said he had been instructed to spy on the airport's security procedures, including passenger screening and boarding processes, and report what he had learned. It said the man who directed the boy had not been located.