Nigeria has detained two executives of the Binance crypto exchange after they flew into the country, media outlets reported. The two were detained by the country's Office of the National Security Adviser and their passports seized, the Financial Times reported, citing people familiar with the matter. The two had been invited by Nigeria to meet officials, and were intercepted when they landed on the grounds that Binance had been operating in the country illegally, people familiar with the matter told Bloomberg. The executives have not been charged, but could face allegations of currency manipulation, tax evasion and illegal operations, Bloomberg reported.